The kind of engine you get in equipment for the next few years will depend on a complex matrix of credits the EPA offers to OEMs.

By Tom Jackson

While the compliance dates for Tier 4 Final engines are staggered from 2008 to 2015, the majority of the engines used in off-road construction equipment will receive Tier 4 Interim engines this year. And in just two years every diesel engine less than 750 horsepower will have to meet Tier 4 Final standards … except those that don’t have to.

The diesel particulate filter is a new and essential component for reducing exhaust emissions but requires additional maintenance.

Unlike on-road diesel engines, most of which all had to meet a new emissions spec on the first day of the year in 2007 and again in 2010, emissions compliant off-road diesels are being phased in by different horsepower bands at different times. (See the chart below.) But, not all engines from all manufacturers have to hit these goals.

Engine manufacturers that did a good job meeting or exceeding emissions targets for earlier tiers of engines received credits, sometimes called flex credits, from the EPA that enabled them to delay implementation of their Tier 4 Interim and Tier 4 Final engines.

Manufacturers that have banked credits may decide to use them now and skip having to put Tier 4 Interim engines in a certain category of machine for the time being. That way they don’t have to spend the money to produce a Tier 4 Interim engine in a machine this year and have to redesign it two years later for a Tier 4 Final engine. But alternatively, a manufacturer may opt to put out machines with Tier 4 Interim engines ahead of schedule, bank credits for these and then use up its credits by delaying implementation of its Tier 4 Final equipment for a few extra years.

Complex but fair

“The EPA’s average banking and trading program for engine emission credits is one of the most complex federal regulations ever in terms of implementation,” says Kevin Kokrda, executive vice president, Engine Manufacturer’s Association. There are people in the engine and OEM world who have based substantial portions of their careers calculating all the permutations of these credits, he says.

Despite the complexity, the flex credit system works out to everybody’s advantage, especially given the huge variety of off-road engines. “It gives manufacturers a smooth way to transition into the engine changes so they don’t have to do everything on January 1,” Kokrda, says. “That would be a big burden from a manufacturing standpoint.” The flex credit system achieves the goals the EPA wants, reducing diesel exhaust emissions by a certain amount by a certain date, while still giving manufacturers options on how to meet those goals.

“Everybody is getting cleaner,” Kokrda says. “There are no laggards. There are incentives built into the program for manufacturers to use the credits in a timely manner, but they can still do what makes sense for their customers and product lines. The federal government was astute in writing these flexibility programs early on.”

What’s under the hood?

For now, equipment OEMs are being tight lipped about their plans for using these credits. You can find out, but you may have to ask. Some machines will have the new emissions technology, and some won’t. Some will be tweaked and some will undergo complete redesigns.

By virtue of the flex credit system OEMs can truthfully say that a certain machine or engine meets the Tier 4 Interim or Tier 4 Final standard, even if it hasn’t changed at all from a previous tier. To find out, ask these two questions of your OEM or dealer regarding their emissions technology:

• What emissions reduction technology is built into the engine on this machine?

• What impact will this technology have on price, performance and maintenance?

Tips for maintenance

Equipment World has written about this technology and its impact on performance and maintenance in previous issues. You’ll find those articles listed in the Recommended Reading box on the opposite page. (Or go to this article on equipmentworld.com/digital and click on the active links).

But here in a nutshell is what you should be paying attention to:

• The biggest change you’re likely to see is the addition of a diesel particulate filter that will scrub particulate matter out of the exhaust stream. These filters periodically purge themselves of the trapped PM, but over time ash from the engine’s lube oil will accumulate and require cleaning. For engines equipped with diesel particulate filters, expect an ash cleanout procedure at around 4,500 hours for engines greater than 174 horsepower and 3,000 hours for engines 173 horsepower and below.

• You must use ultra low sulfur diesel fuel and low-ash lube oil (designated with the American Petroleum Institute’s CJ-4 certification) to prevent premature clogging of your DPF.

• Many engines will increase the amount of exhaust gas recirculation and generate more heat. In addition to larger cooling packages, many of these will come with new extended life coolants as the factory fill. These new ELCs form a much thinner coating on the inside of your radiator surfaces and hence do a better job of radiating heat out to the atmosphere. Just don’t make the mistake of putting conventional coolant in these machines and negating all the positive effects of the original ELCs.

• Pay attention to the quality of your fuel. Most of these machines are common rail, high- pressure injection with multiple injection events. The openings in the injectors are too small to tolerate much water or debris in the fuel.

Costs and other considerations

The machines that get the new technology will see price increases. Again, the OEMs are playing this one close to the vest, but most industry observers think that overall machine prices will increase anywhere from 5 to 15 percent. A lot of these will be model changes with significant other upgrades and improvements, but most of the increase will be to cover the costs of the emissions technology development and implementation. When you consider that an engine is roughly 10 percent of a machine’s cost, that means in some cases the price of the engine is more or less doubling.

Fleet managers respond

“If the fuel savings and improvements help offset the increase in cost, that will be a benefit, but I’m somewhat skeptical of that,” says Robert Merritt, CEM, director of maintenance at URS, Boise, Idaho, a large construction services firm.

Maintenance for the new exhaust emissions systems is also presenting new challenges. “The field technicians have difficulty diagnosing problems today, much less new technology,” says Ron Sharp, equipment manager at Armstrong Coal, Madisonville, Kentucky. “Dealers will have to increase training above the levels we have today, and that only adds cost.”

Both men say the emergence of the new technology will change how they look at equipment lifecycles and acquisition strategies. “We will retain equipment longer and strongly consider pre-Tier 4 equipment says,” Sharp says.

Dan Samford, vice president of corporate equipment at St. Joseph, Missouri-based Herzog Contracting, accepts the inevitability of emissions compliant equipment, but says when the lifecycle allows it he may also hang on to older equipment longer than before. He anticipates a few bugs being worked out in the first few years and plans to rely on dealer and OEM for some maintenance and technical assistance. EW

RECOMMENDED READING

Go to equipmentworld.com/digital and click on “issues” in the top menu bar to access these articles:

Tier 4 Interim, September 2010, page 43.

Hauling Ash, June 2011, page 23.

Five questions, September 2011, page 39.

The new cool, November 2011, page 35.

New year-new engines-new oils, January 2012 (digital edition)

Knowing how to keep your hydraulic fluid healthy pays big dividends

Today’s construction machines perform at levels unheard of only a few years ago, thanks mostly to advances in hydraulic pumps. But with their high pressures and close tolerances these pumps require you to step up your game when it comes to maintenance and contamination control.

Keeping your hydraulic fluid cool, clean and dry isn’t rocket science, but it does require vigilance and knowledge of what’s going on inside the system. Failure to do so almost certainly will result in costly repairs (tens of thousands of dollars) and extensive downtime.

“There is a misconception that machines that have a sealed system and filters should run clean from the beginning until it’s time to replace the filters and oil, but that is not the case,” says Diego Navarro, service marketing manager, at John Deere Construction and Forestry.

External contamination, primarily dirt (alumina/silica) and water or humidity can work its way past even the tightest system. “Just because the hydraulic cylinder is shiny and dry doesn’t mean that it isn’t bringing in dirt and water,” Navarro says. “There are no 100-percent sealed systems. They all leak some.”

Normal operation will admit small amounts of external contamination. And hydraulic fluid over time oxidizes, the additives degrade and the fluid picks up a certain amount of wear metals – all to be expected and cured with new oil and filter at the scheduled maintenance interval. But there are plenty of other sources of external and internal contamination you have to guard against as well.

EXTERNAL CONTAMINATION

Uncorrected leaks. “If you have a cylinder that’s leaking, it’s guaranteed that you will have dirt or humidity in the system,” Navarro says. “If leaks can get out, dirt can get in.”

Filtration caddies can clean and recirculate hydraulic fluid without having to drain the reservoirs.

Service practices. How clean is your service truck and its containers? Do you filter the fluid before it enters or leaves the truck? Are your funnels, rags, service equipment clean? Even something as simple as repairing or replacing a hose can introduce significant contamination.

Attachments. Hydraulic hammers can put a lot of wear metal and sometimes dirt into the fluid. All it takes is a few minutes of operation for the dirty fluid in the hammer – or any other attachment – to circulate into the host machine’s hydraulic fluid system. Cross contamination between machines is also feasible when they share the same implement.

Mixing. Not all hydraulic fluids are alike. If you top up or refill with a different spec fluid you could seriously compromise to performance of the fluid.

INTERNAL CONTAMINATION

Wear metals. Like engines, hydraulic pumps wear over time and the fluid will pick up trace amounts of iron, copper, lead and other metals.

Surface degredation on the pump pressure side caused by fluid contamination.

Resident contamination. Most machines come with clean fluid from the factory, but with hundreds of feet of hydraulic hoses and lines and multiple pumps and cylinders there is always the chance that some contamination may reside in the machine upon delivery. This shouldn’t be enough to warrant remedial action, but it does add to the cumulative total over time.

Catastrophic failure. Should a hose or seal break down, or a component within a hydraulic pump disintegrate, the residue will quickly spread throughout the system. A catastrophic failure on the slipper side of the pump is less severe than one on the pressure side of the pump.

Varnish. This is created when you have a high pressure leak that produces foaming and high temperature in the fluid. In these conditions micro-dieseling occurs (something similar to cavitation). Micro-dieseling in the presence of iron particles (catalyst) gives you varnish. Varnish particles are very small and can stick to sump and valve parts compromising their performance. Navarro says varnish isn’t too common, but he compares it to cholesterol in humans. “You have to clean it and fix the machine,” he says. “Sometimes you can save the machine from major damage, but typically people react, when the pump is already in trouble and it’s too late.”

OIL SAMPLING AND ANALYSIS

As with engine oils, sampling and analysis is the key to identifying these problems and figuring out a solution.

With water comes rust, here coating the top of a hydraulic tank.

Since hydraulic fluid isn’t contaminated with combustion byproducts like engine oil, it lasts longer. The typical change interval can be anywhere from 1,000 to 4,000 hours. But you should sample much more frequently than you change hydraulic fluid. Navarro recommends it every 250 hours, as do many OEMs. At a minimum you should sample every 500 hours.

Mark Minges, chief operating officer for POLARIS Laboratories, recommends monthly sampling for any system or component that is critical to your operation. But, he admits, quarterly sampling is more typical.

Contamination damage: The rear pistons have deteriorated and one of the slippers fractured (left). Component wear spreads shrapnel throughout the system (right).

Monitoring wear is important, Minges says, but the real advantage to testing hydraulic fluids is to keep them clean enough to prevent valves from sticking, moving parts from wearing and dry enough for optimum system performance.

Particle counts are also critical. “The number one killer of pumps is high contamination of solid particles,” Navarro says.

Minges adds that you should test viscosity, which indicates oxidation and fluid degradation. And check the acid number, which is relevant if the fluid is stressed, he says.

Who is Karl-Fischer?

Rust isn’t just a surface problem. It can spread particles throughout your system (left). Slipper side corrosion due to contaminated fluid (right).

Water is the second leading killer of hydraulic pumps and also a major item to check in hydraulic fluid analysis. Water more than 500 parts per million can be detrimental to hydraulic system operation, Minges says. Water more than 1,000 ppm will cause corrosion and give the controls a spongy feel or make them unresponsive.

To test for the presence of water in hydraulic fluid, Navarro and Minges recommend something called a Karl-Fischer test. You should ask for this by name because not all labs are equipped to do it. It’s a standard test for POLARIS Laboratories, Minges says, to screen samples with what’s called a Crackle test and then run a Karl-Fischer test to tell you how much water is present.

“The Karl-Fischer test allows you to see water below 100 ppm,” Navarro says. “The infrared test normally offered is blind to water until it’s about 1,500 ppm. So your visibility of water without Karl – Fischer is limited.”

Navarro cautions that some fleet managers underestimate the importance of water detection, or balk at the cost. “If you’re going to spend $10 for a regular sample or $13 for one with Karl-Fischer, I would do it with Karl-Fisher,” he says.

CHANGING AND FILTERING OIL

Hydraulic oil filters on your machines guard against a lot of the contamination you’ll encounter in normal operating conditions. But there are several ways to improve on that process as well.

Bypass filters. These are popular options in some applications and machines. A bypass is nothing more than a secondary filter that takes a small amount of oil and super cleans it before returning it to the sump. This super clean oil continually raises the cleanliness of the whole system. “Some people worry that with a bypass filter you won’t see wear,” Navarro says, “but you’ll see it on your oil analysis, although the threshold needs to be adjusted.”

Fluid caddies. These carts range from $2,000 to $10,000 and are used to siphon old fluid out of the hydraulic system, clean it to a desired spec and then return it to the machine. The more expensive versions measure the fluid cleanliness and continue to filter the oil in the system until it reaches a target level of cleanliness. The lower cost models simply work for a designated period of time. (See the resource box at the bottom of the page for more information on manufacturers of these carts.)

Flushing calculator. On engines when you drain the lube oil you remove about 95 percent of it. When you drain a hydraulic system, you only capture about half. The rest remains in the hundreds of feet of hoses and the pumps and cylinders. A flushing calculator is an Excel or spreadsheet type program that shows you how many times you have to flush and refill the hydraulic reservoir to get the whole system back to 95 percent or better. The numbers will vary with the size and type of machine, but in general you have to flush the system three times to get to 98 percent purity, and six times to get to 100 percent. Talk to your OEM dealer or lubricant supplier about getting a flushing calculator for your machines.

See our interview about today’s hydraulic oil filtration standards in our digital edition:

equipmentworlddigital.com

RESOURCES: FLUID CARTS

Pall Corporation: www.pall.com

Trico: www.tricocorp.com

Hydac: www.hydacusa.com

Internorman: www.internorman.com

Stauff: www.stauff.com

Organic acid technology in extended life coolants can just about last the life of your engine without replacement or additives. But that doesn’t mean you can ignore maintenance requirements.

By Tom Jackson

If heat is an engine’s greatest enemy, a new generation of extended life coolants has taken the to the field and is fighting back hard.

The first appearance of these new coolants dates back to the mid-1990s with the introduction of what’s called organic acid technology or OAT. Since that time the benefits of extended-life OAT coolants have proven themselves to the point where they’ve become the factory fill for most diesel-burning yellow iron, heavy trucks as well as many gasoline-burning light-duty trucks and vehicles.

If you have a new piece of equipment or a new truck with OAT coolants flowing through the system the important thing to remember is to not top it off or refill with a conventional coolant. The good news is it may be years before you have to change the coolant. Today’s premium products can go as much as 12,000 hours or 600,000 miles before they need changing.

Coolants have three parts – water, ethylene glycol and the additive package – explains Stede Granger, OEM technical manager for Shell Lubricants. What makes OAT coolants different from conventional coolants is the additive package and the way it protects against corrosion.

“Conventional coolants work by plating out on the surface and providing a mechanical barrier to corrosion inside your cooling system,” Stede says. “But it takes a lot of the coolant additive to do that. After a while, the additive gets used up and you have to replace it. On light-duty applications you just change the coolant. On heavy trucks and equipment with large cooling systems you put additives back in.”

At one point in time, putting in supplemental coolant additives, or SCAs, rather than performing a complete flush and fill, helped big truck fleets extend coolant life and cut down on maintenance costs. But SCAs didn’t offer the same performance benefits as do OAT-based additives.

Bill Dusing, North American coolants team lead at Chevron Lubricants, describes the corrosion barrier formed by conventional coolants as a blanket of insoluble, inorganic salts. “Like a foam fire extinguisher putting out a fire, conventional inhibitors not only cover the hot spots, but everything else around it,” he says. “A large portion of the conventional inhibitor package is consumed to create this blanket. Also, like any blanket, the conventional inhibitor blanket tends to hold in engine heat, slowing the heat removal process.”

By contrast OAT inhibitors work on an electrochemical basis. When a point of corrosion appears inside your system, OATs are chemically attracted to that spot and stop the corrosion process in its tracks. “In this process you’re attracting molecules instead of big globs of the additive,” Granger says. “We’ve done tests on the big trucks with ELC at 600,000 miles and they will still have 95 percent of the additive left, whereas conventional coolants would have been depleted many times over. With ELC, the additive is only used when needed and only in small amounts.”

As a result, interior surfaces of your radiator and water pump stay cleaner and heat transfer is more efficient, but you can compromise that performance if you top up with or refill your system with conventional coolants. “It disappoints me when I see somebody with a large piece of equipment or a large truck with a cooling system of 120 or 150 gallons and they start dumping in a silicate coolant and contaminating the heat transfer surfaces,” Granger says.

The other big benefit to OAT-based coolants is that they protect the water pump and water pump seal against failure. Conventional coolants typically contain silicates and phosphates which may form deposits on seal faces causing abrasive wear to the seal surface resulting in leakage. Extended life coolants based on carboxylate corrosion inhibitors form fewer deposits and are not as abrasive to water pump seals. One of the primary reasons most truck and car manufacturers have switched to OAT coolants is that they reduce water pump failures and warranty issues.

Nitrites … or not

Nitrites have been part of the additive package in coolants since well before the introduction of OAT technology. The primary role of nitrites is to prevent cylinder liner pitting in diesel engines. Today’s OAT coolants do just as good a job of protecting against liner pitting without nitrites, but ELC manufacturers continued to put nitrites in their formulas to provide backup protection.

“We found out we didn’t need to put nitrite in there,” Granger says. “It was redundant. But in the meantime we found out that while nitrite is good for cast iron, it’s not good for aluminum. Under certain conditions you can have a nitrite aluminum reaction.”

“Cooling systems are more complex than one might think,” Dusing says. “Copper/brass combinations are still frequently used in heat exchangers as well as thermostats. Older or larger diesel engines will be cast iron. But steel is used in water pump impellers and in some cases even galvanized materials are used in core plugs and some tubing.”

Since lot of newer engines are using aluminum in-their cooling systems, most ELC manufacturers offer nitrite free formulas.

Not long after they were introduced, there was some speculation that OAT formulas could erode lead solder in cooling system joints. But Granger, who has spent 18 years investigating cooling system failures in the field, says he’s never seen a case that proved this allegation.

A more likely culprit, says Dusing, is a failure to monitor the cooling system pH. “When the pH drops the coolant becomes acidic and can attack the lead solder joints along with other components of the system including gaskets, rubber and aluminum,” he says.

ELC maintenance tips

With all these wonderful attributes you might think that the maintenance mantra for OAT coolants would be “fill it and forget it.” But that’s not quite right. Here are the new rules:

1. As mentioned, the most important thing to remember about cooling system maintenance on new equipment or vehicles with ELCs is not to top up or replace the OAT coolant with conventional coolant. Your best bet is to find out what the factory fill is and stick with that or something that meets the same specs and has the same chemistry.

2. Check with your equipment or truck manufacturer to find out if they require nitrite free products or not. Many do. Using the wrong product will likely lead to cooling system failure.

3. If you use concentrated coolant to be mixed 50/50 with water make sure you use de-ionized water. Minerals in ordinary tap can water negate some of the benefits of ELCs or interfere with their chemical effectiveness. If this is not practical, buy the premixed/pre-diluted formula. That eliminates the possibility of errors and the premixed formulas are easier and quicker to use when topping up.

4. Check your coolant pH at regular service intervals. This will alert you to excess acidity that may attack lead solder, gaskets and other materials.

5. Also check your freeze point with a refractometer on a seasonal basis. “With ELC your freeze point is just as important in July as it is in January,” Granger says. “With conventional coolants in the summer people used to top off with water and then add a little antifreeze to bring the freeze point down when it starts getting cold. With the older coolants you could get away with it because you’re adding additives all the time. With ELCs you’re not replacing additives and if you add more water you dilute the additive package and might lose your corrosion protection or your ability to prevent liner pitting.”

Ethanol is bad for engines, a big tax subsidy for corporations and bad for the environment. So why does EPA want to make us use more of it?

By Tom Jackson

Ethanol is a great social lubricant. It puts the buzz in booze, but it has the opposite effect on engines – especially small ones. It’s corrosive and loves water – think bourbon and branch water, scotch on the rocks.

When it was first introduced as a fuel in the 1980s it was a disaster. “At that time there were tremendous problems with equipment and vehicles,” says John Foster, manager of product compliance at Stihl. “Material compatibility issues were very common. Some cars just stopped in their tracks after getting a tank of that fuel.”

Automotive re-engineering

Since the 1980s most vehicle manufacturers have come up with gaskets, seals and fuel injection equipment that could handle the stuff. And most people burn through a tank of gas in a matter of a week or two, so the ethanol doesn’t have much time to absorb water out of the atmosphere. Some automobile manufacturers have even designed engines and fuel systems that can run on 85 percent ethanol or E85. These are distinctly labeled as “Flex-fuel” vehicles.

Today, unless you look hard, you won’t find any gasoline that isn’t blended with 10 percent ethanol, or E10 as it’s called. For most automotive and truck applications, this seems to be tolerable. (Although last year Lexus had to recall more than 200,000 cars to fix ethanol related damage.)

But if you use gas-powered equipment – jumping jacks, generators, concrete saws, jackhammers, powered screeds and trowels, breakers, post-hole diggers, welders and generators – ethanol still poses problems. Unlike automotive applications, where most users burn through a tank of gas in a week or two, the gas used in many small engines may sit for months at a time in unpressurized containers. Long storage times in open containers means the ethanol will absorb more water. Even pure gasoline will absorb some water and degrade over a season or so, but many small engine users report E10 gas going bad in less than two months.

Mechanic’s nightmare

Small engine repair shops across the country universally condemn the stuff and blame it for a rising tide of equipment failures and problems. To protect their customers’ equipment, several of the leading portable power equipment manufacturers are now selling their own proprietary ethanol-free gasoline. This gasoline is also premixed with lubricating oil for two stroke engines. It comes in sealed containers – you only use it as needed, so there is less opportunity for the ethanol to absorb water out of the atmosphere.

Pushback on E15

The EPA is now pushing for a new E15 ethanol mandate. The EPA’s justification is a law passed in 2005 called the Renewable Fuels Standard, or RFS, which requires the U.S. to use at least 36 billion gallons of renewable fuel annually by 2022. But the RFS law never took into account rising fuel economy standards, and Foster says he doubts the country can meet that goal even with E15.

The difference this time is that industry is pushing back against the overly aggressive promotion of ethanol.

In April, Kris Kiser, executive vice president of the Outdoor Power Equipment Institute told Congress: “No engine product in our legacy portfolio or coming off the production lines today is designed, built or warranted to run on any gasoline fuel containing more than 10 percent ethanol.”

Kiser also documented what might happen to small engines running on E15. This included excessive engine heat, melting of plastic guards, fuel leaks, evaporative emissions issues, unintended/early clutch engagement and permanent engine damage. (See Kiser’s full testimony at http://www.opei.org/news/detail.dot?id=17126). Ethanol has a higher octane number than gasoline so the likelihood of your engine racing on E15, rather than running at the correct speed, is considerable.

Additionally, nine automakers, foreign and domestic, told congress they won’t honor warranties on older vehicles running E15. In a public letter to Congress, Thomas Baloga, vice president of engineering for BMW in the United States wrote of E15: “Damage appears in the form of very rapid corrosion of fuel pump parts, rapid formation of sludge in the oil pan, plugged filters and other damage that is very costly to the vehicle.”

Leading the charge against E15 in Washington D.C., congressman Jim Sensenbrenner said, “Automaker responses overwhelmingly show that E15 will damage engines, void warranties and reduce fuel efficiencies. Americans need a fuel that will give them more miles out of a gallon of gas and extend the lives of their cars, not that will prematurely send their vehicles to the junkyard.”

Congress capitulates

This summer the Senate voted to end corn-based ethanol’s 45-cents per gallon tax credit given to the oil companies for blending ethanol with their gasoline. It looked like good news for anti-ethanol advocates, but the House refused to follow suit and let the bill die thus continuing a $6 billion subsidy for ethanol.

Even if a future Congress eliminates the subsidy, ethanol will have to be consumed in ever greater quantities unless the federal government repeals the RFS law. In fact, everything right now points to an E15 blitzkrieg that will sweep over the country within a year. The Government Accounting Office has said it may take up to a year before all the logistical problems are worked out in the ramp-up to E15. But the process is moving forward.

“In theory at this stage, E15 can only be used in flex fuel vehicles,” Foster says. “But you’re going to hear about some stations in the corn belt already dispensing E15 and there are questions as to the legality of that.”

Voodoo economics

One of the original justifications for E10 was that it would reduce imports of foreign oil and thus help our domestic economy. That hasn’t happened.

A research paper by Craig Cox and Andrew Hug for the Environmental Working Group showed that corn-based ethanol biofuel is wasteful, inefficient and a misuse of taxpayers money.

Other countries report similar results. In April the German news magazine Spiegel commented on that country’s brief flirtation with the fuel, writing: “An attempt to introduce the new biofuel mixture E10 in Germany has been a disaster. Even environmentalists oppose the new fuel.”

A step back for the environment

E10 blended gasoline was supposed to contribute less to ozone formation, a component of smog, and reduce greenhouse gas emissions, according to the EPA’s studies. But that research has come under increasing criticism over the past few years.

Stanford University recently published a study that showed ethanol produces slightly more ozone than regular gasoline and produces emissions that are substantially higher than gasoline in aldehydes, the carcinogenic precursors to ozone.

And the list of American environmental groups opposed to ethanol in fuel is startling, including the American Lung Association, Friends of the Earth, the Natural Resources Defense Council, the Sierra Club, and the California Air Resources Board.

In addition to its unhealthy effect on our air, corn-based ethanol is widely criticized for consuming vast amounts of water, land and fertilizer. It takes 300 gallons of water to grow enough corn to make a gallon of ethanol. And diverting more than 40 percent of our corn crop to making fuel, critics say, is raising the cost of food across the globe.

What to do for now

Even if the EPA can convince gas station owners to put in additional underground storage tanks for E15, Foster says there is a great concern about misfueling. People filling their gas tanks may not check the pump label and inadvertently fill their gas cans, ATVs or portable power equipment from the same dispenser at the same time. If you’re a contractor and send a go-fer out to tank up the equipment next year you could be looking at a disaster if he chooses the wrong fuel.

Keep your eyes on those labels (especially if you live in the Midwest) and protect your portable power equipment with these suggestions:

1. Use manufacturer recommended fuel treatments for everything you put in your gas-powered equipment. Fuel stabilizers have been used for years and most manufacturers have additives now that help compensate for the effects of ethanol as well.

2. Get rid of any ethanol-blended gasoline after two months.

3. Find sources of ethanol-free gasoline. They’re rare, but most mid-sized towns will have at least one service station that sells it.

4. If your construction business is a major purchaser of portable power equipment, have a long talk with your dealers or manufacturers about the warranties on this equipment and get guarantees in writing. The long term effects of ethanol on small engines is not well known, but if your equipment isn’t lasting as long as it used to you may want to contract for extended warranties.

5 Questions you should ask before launching an extended drain interval program

By Tom Jackson

To meet the many new exhaust emissions regulations, diesel engines have undergone more changes in the past eight years than in the previous 50.

The good news is the new engines still crank out plenty of torque-heavy power and do so with more fuel efficiency and cleaner exhaust than ever before. But one of the biggest challenges for fleet managers is understanding how the new engines, lube oils and fuel affect oil drain intervals.

Regardless of the year model of engine you are working with, there are five questions you have to ask before you can move forward on an extended drain interval program in today’s greener world.

QUESTION 1

What do you hope to achieve with an extended drain interval?

Defining your goals prevents you from doing something just to be doing something. Extending your lube oil drains just so you buy less oil can be a false savings. The oil drain interval is often a trigger for other maintenance events, inspections and safety reviews and those should be considered as well.

“Say you have a grease that can only go 250 hours,” says Dan Arcy, OEM technical manager for Shell Lubricants. “Even if you can go out to 350 hours with your oil drain interval, does it make sense to take that piece of equipment out of service at the 250-hour period if you’re not also going to change the oil? It may be a net loss to do that based on the productivity of the equipment.”

Arcy says he prefers the term “optimized” drain interval, rather than “extended.” Optimized implies that you are finding the best balance between the goals of protecting the health and longevity of the engine, saving money on maintenance and maximizing uptime. If you’re dealing with a lot of different types of equipment or equipment in different applications and environments, an optimized drain interval may mean one that’s timed at a service interval chosen for the worst case scenario – when the first fluid, oil component or grease that reaches its limits, Arcy says. Most fleet managers may not want to manage a lot of different drain intervals.

QUESTION 2

What are the limiting factors on my oil?

Most engine manufacturers publish specs on how much contamination or degradation they will allow in their lube oil. Once this limit is reached, you have to change your oil or face the consequences.

The challenge for today’s fleet managers is that those oil limiting or condemning factors have changed along with changes in engine design, emissions technology, ultra low sulfur diesel and new lube oil formulas. Here’s a summary of the major changes:

• Soot and heat increased in on- and off-highway engines from 2003 to 2010 with the increase in exhaust gas recirculation (EGR) to combat emissions.

• With the switch to selective catalytic reduction (SCR) technology in 2010, heat and soot became less of a problem for the oil.

• The use of diesel particulate filters (DPFs) both on- and off-road has significantly cut the levels of soot in the oil.

• The introduction of ultra-low sulfur diesel fuel for highway trucks in 2007 and for on- and off-road use in 2010 reduced the amount of acid formed in the oil and thus reduced the likelihood that TBN (or total base number) would be a condemning factor.

• Off-highway engines generally mirror the changes in on-highway, just three years later, with Tier 3 emissions standards being phased out and Tier 4 Interim and Tier 4 Final being phased in from 2008 to 2015.

• The new CJ-4 oils introduced in 2007 have reduced levels of sulfated ash, phosphorous and sulfur (called low SAPS oils). They protect the exhaust emissions componentry and offer better deposit control, improved wear protection and improved oxidation stability.

• The new synthetic or partial-synthetic oils, may help performance in some severe conditions. Their strong suit is engine protection especially against wear – offering high temperature oxidation stability. They also offer better cold flow properties which makes engines easier to start in severe cold conditions.

So oil chemistry has changed for the better and the contaminants and oil limiting factors have changed, some for the better some for the worse. Still, drain intervals are not as a general rule, getting longer. There may be six or eight potential condemning factors to watch for in your engines’ oil, but it only takes one of them to reach its limit to trigger an oil change.

“One of the myths I often run into is that synthetic oil allows you to extend your drain interval,” Arcy says. “But whether you have a mineral oil or a synthetic oil, if it’s condemned because of the soot level or dirt contamination it doesn’t matter. You don’t have the ability to go any further.”

QUESTION 3

What changes with my oil analysis?

Despite all these changes, one fundamental fact remains. To extend your drain intervals you need a good oil sampling and analysis program. And that begins, not with a spreadsheet and sample bottles, but a conversation with your oil analysis lab.

The new American Petroleum Institute CJ-4 standard meets a higher spec than any other lube oil that came before it, but it does not by itself allow you to extend drain intervals.

One of the first questions you need to ask is: do you have the right test package for an extended drain program? “A basic test package doesn’t include certain tests,” says Mark Minges, chief operating officer at Polaris Labs.

The three critical tests you need for extended drains include:

• Total base number (TBN). This measures the depletion of the detergent package that neutralizes the acids that build up in the oil.

• Oxidation/nitration. As the oxidation increases, the TBN depletes faster and the oil ages, eventually becoming unsuitable for use.

• Viscosity.

In addition to these elements for extended drains, any oil analysis should also include tests for wear metals, coolant, dirt, water, fuel dilution and soot.

“Our philosophy is that as long as the oil isn’t severely contaminated, as long as there is still base in the oil and oxidation and nitration levels are kept in check or below the warning limits then we’ll extend the drain out as far as possible,” Minges says. “If there is any contamination or an alarm level of contamination then all bets are off. What we don’t want to do is sacrifice the engine to extend the life of the oil.”

“I haven’t seen a fleet yet that we haven’t been able to extend to some degree.”

– Mark Minges, Polaris Labs

Even if you do decide to extend your intervals, Minges recommends to test your oil at the regular interval just to keep an eye on unforeseen problems that may prove catastrophic such as a breach in your air filters, or a sudden spike in wear metals. The use of an oil sampling port (see sidebar below) can make this sampling easier and less prone to contamination.

“Oil analysis is a window into your engine,” says Kevin Kroger, president and COO of puraDYN Filter Technologies. “It tells you what’s going on in your engine and the condition of your oil. It has to be a disciplined program, especially initially as you establish your hours. Oil analysis will help you get there safely.”

Question 4

What should I do about my oil filters?

Assuming you want to save money and decrease downtime with an extended oil drain interval, one component you need to pay careful attention to is your lube oil filter.

“When you step outside the norm for drain intervals, you put more stress on the filter,” says Paul Bandoly, manager of technical services/customer training at Wix Filters. “The gasket that’s compressed between the engine and the filter base has to last longer. “The filter media has to be robust and durable enough to last for longer periods of time.”

Oil pulses through filters, and the unsupported cellulose media in traditional filters runs the risk of tearing as it gets hammered by these pulses in longer than normal duty cycles. To prevent this from happening in extended drain intervals filter manufacturers often use synthetic filter media and some kind of wire or mesh support, says Bandoly. “The fully synthetic sheets with the wire backing don’t flex the same, and since they don’t absorb moisture they don’t weaken, like cellulose,” over time, he says.

Bypass oil filtration is also frequently used to keep oil cleaner during extended drain intervals, says Neha Takawale, global product manager-lube filtration for Cummins Filtration. A bypass filter is a separate filter that siphons off a portion of the oil and cleans it, thus continually diluting the dirty oil with cleaner oil. Some bypass filters are included within the canister containing the full flow filters, some are housed in separate units.

With their high EGR rates and idle times, off-road machines often see a rapid buildup of soot in the oil, and bypass filtration is especially useful when dispersed soot content is the limiting factor on the drain intervals, Takawale says. And since soot particles are often sub-micron in size, they are difficult to trap in conventional cellulose or synthetic filter media of full flow filters.

Question 5

Go or no-go?

Making the choice as to whether or not to extend your drain intervals should not be attempted until you’ve answered the above questions and discussed these issues with your equipment dealer, lube oil supplier, filter manufacturer and oil analysis lab. Only then can you identify your goals, plot a strategy and pencil it out to make sure it makes sense.

But the potential to save your company significant money and improve uptime is a likely benefit.

“With most of the samples we get from engines, I can look at the data and say there is no problem extending their oil drain out,” says Minges. “It depends on the unit, the duty cycle, the environment it operates in and the operator. But most companies change their oil too soon, and I haven’t seen a fleet yet that we haven’t been able to extend to some degree.”

Oil sampling ports

Taking a clean oil sample from a warm or hot engine is tricky business. Pull a sample from drained oil and you pick up contamination from the drain plug, the oil pan, the collection container – anything that the oil touches. Vacuum pumps that suck oil out of the engine compartments are less prone to contamination but still require careful handling.

The best solution is to install an oil drain valve like the one shown here from Fumoto Engineering of America. Tapped into the oil lines upstream of the filter, the valve enables you to simply turn a lever to release oil and turn it back when your sample jar is full. Do it when the engine is warmed up and running and you get the most accurate sample possible. Even better, you can teach operators how to capture a sample in the field and avoid downtime or having to schedule a service tech to do it.

For more information see www.FumotoUSA.com.

Extended drain filters

Off road and truck fleet managers are under the gun to keep machines out of the shop and in the field as much as possible. To that end, filter manufacturers have come up with several innovative solutions that have the potential to cut the number of oil changes you may need in half.

Donaldson’s Endurance filters balance efficiency, capacity and restriction using the company’s Synteq filter media. While delivering low restriction and maximum flow, the synthetic filter media remove more than 90 percent of the contaminants that are 10 microns or larger compared to 50 percent for cellulose.

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The Venturi Combo filter technology from Cummins Filtration consists of a section of full flow StrataPore synthetic media and a stacked disc layer consisting of high efficiency bonded cellulose media. The gradient density of the StrataPore media provides progressive removal of contaminant fine particles. The venturi nozzle in the filter works on the principle of pressure differential and directs more oil through the stacked disc media for high efficiency filtration without restricting oil flow.

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Using what the company calls “Spin Flow” technology, the Wix XD Filter is a full flow bypass filter with channels in the top that direct the flow of the oil down the length of the element for a better mixture of the full flow stream exiting the filter. Instead of turbulence at the top of the filter, the XD filter efficiently uses the full length of the filter. Wix’s ecoLAST filter has a proprietary media that sequesters the acid in the oil that passes through it without changing the chemistry of the oil. That extends the TBN, which slows down the oxidation and degradation of the oil.

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Excess oil consumption in an extended drain

In addition to oil analysis you’ll want to keep an eye on oil consumption during an extended drain interval, says Kroger. Sometimes at the recommended drain interval, 250 or 500 hours, the oil may still be within the manufacturer’s specs for condemning factors but have just about depleted a percentage of its additive package.

When this happens the oil won’t lubricate as well and you’ll see increased oil consumption. As the oil begins to lose its lubricating properties it is more easily carried through different avenues into the combustion chamber where it is consumed. “You see a little more oil consumption because the oil is losing the characteristics that allow it to do its job, thus the importance of bypass filtration to keep the oil continuously clean and maintain its chemical balance,” Kroger says.

The change is small and the oil is still providing engine protection, but it would be wise to check the oil levels and top off when needed on any machine in an extended drain program.

The puraDYN Bypass Filter, used in conjunction with the equipment manufacturer’s full flow filter, keeps engine oil cleaner by cleaning a small amount of oil out of the normal stream and returning it back into the flow while also removing water and contaminating gasses. In addition the filter contains timed-release, additive pellets that replenish anti-oxidants, wear inhibitors and TBN and maintain viscosity as they become depleted from the oil. The filter also uses a treated element that chemically attracts and then binds contaminants less than one micron in size.

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Natural gas and propane autogas

These are truly “green” fuels, all-American, cost competitive and loaded with horsepower. For medium- and heavy-duty truck applications, though, these fuels can’t be beat.

By Tom Jackson

It used to be simple. There was diesel, and there was gasoline.

Now there’s gasoline, E10 gasoline-ethanol blend, E15 (maybe), E85, diesel, ultra-low sulfur diesel, B5 biodiesel, B20, B100, propane autogas and natural gas.

And, as if keeping up with all these new fuels wasn’t enough, as an equipment owner or manager you have to come up with different maintenance processes and protocols for each type of fuel. Failure to adapt to the peculiar maintenance requirements of each fuel could compromise anything from a $300 chainsaw, to a $50,000 truck or a $600,000 bulldozer.

There’s a lot to cover in this topic so we’ve broken it down into a three-part series. This month we’ll talk about natural gas and propane autogas used in trucking applications. In the months to come we’ll write about ethanol-gasoline blends and biodiesel.

Which gas is which?

There are a lot of terms thrown about when it comes to describing natural gas and propane, which leads to some confusion. But when drilling companies tap into underground gas deposits, what comes up out of the hole is a mixture of methane, propane, propylene and butane. The important ones for our discussion are methane and propane. Here’s how they compare:

Methane (often called natural gas) has qualities that make it useful as an industrial fuel, but it has to be compressed or chilled to turn it into a liquid, which adds some cost and complexity when used in automotive or truck applications. The acronyms used to describe it as a fuel are CNG (compressed natural gas) or LNG (liquid natural gas). Natural gas has a high octane rating –120 to 130 – which makes it best suited for high-compression engines, built specifically for CNG or LNG. Natural gas has about 20 percent less energy density than diesel but it sells for the equivalent of $1.70 to $1.90 a gallon.

There are a variety of state incentives for natural gas use. To find out what your state offers go to www.afdc.energy.gov/afdc/fuels/natural_gas_laws.html and click on the map.

Propane can be stored as a liquid at relatively low pressure (about 200 psi) and has none of the storage and handling complications of CNG and LNG. It’s the same stuff that powers home heating systems and barbeque grills. Sometimes the acronym LPG (liquefied propane gas) is used to describe it, however for automotive applications the preferred term is now autogas or propane autogas. Propane also has less energy density than gasoline, so to get the same range as a gas engine, propane powered vehicles need larger fuel tanks. But that’s its only drawback. You need a pressurized fuel storage system, different injectors and hardened valve seats to make a propane engine work, but these aren’t difficult to add as retrofits or build into new designs. Propane is currently selling for about $2.15 per gallon equivalent.

For state propane laws and incentives go to www.afdc.energy.gov/afdc/Fuels/propanelaws.html.

One of the most important attributes of propane and natural gas is that they are the best fuels when the goal is to reduce imported oil. Ninety percent of the propane used in the United States is produced in this country, and gas well drilling and exploration is fueling a major boom in heavy construction in Western Pennsylvania, southern and eastern Texas, and Wyoming and Montana. Natural gas already accounts for 24 percent of the electricity generated here.

On the environmental side, natural gas and propane autogas burn much cleaner than gasoline or diesel. Emissions of greenhouse gasses and exhaust pollution are as much as 24 percent lower than traditional fuels on a gallon-per-gallon equivalent.

Ford’s push to propane

Ford has been interested in the alt-fuel universe for quite some time, says Joe Thompson, president of Roush CleanTech. And when the blue oval engineers tasked the Roush engineers to find the best alternative to gasoline in its medium- to heavy-duty trucks and vans the answer came back – propane. Their reasons?

• Performance: Propane performs as well as gasoline in terms of horsepower and torque (see chart below).

• Cost/benefit ratio: The cost of the vehicle hardware is reasonable and lower than any of the alternatives says Thompson. Roush CleanTech on its website (www.roushcleantec.com) has a calculator you can use to figure the propane installation costs for its trucks or vans. In one example it costs about $16,000 to convert a new Ford F-450 or F-550, but 200,000 miles later the owner will save almost $33,000 in fuel costs (compared to gasoline at $3.50 per gallon). As the price of gasoline goes up the payback point comes earlier. The breakeven point typically lands somewhere before the middle of the vehicle’s first lifecycle. The bigger the engine, the better the payoff.

• Pumps often free for fleets. Propane pumping station costs vary but average about $20,000 to $50,000. But many of the gas companies such as Ameri-Gas, Ferrellgas and Heritage Propane will put in a pumping station for free in return for the fuel contract, even if you have a relatively small fleet, as few as eight trucks in some cases. In addition to propane costing less than gasoline, end users who have their own propane pumps can collect a 50-cent-a-gallon tax rebate from the Federal government. Note that this tax credit may expire at the end of this year unless Congress decides to renew it.

Keep it simple

Roush CleanTech also chose the propane route because of its mechanical simplicity, Thompson says. Basically, all you change is the fuel tank, the fuel lines and the fuel injectors. For retrofits on some earlier models of Ford trucks and vans, hardened valve seats and new heads may be required as propane lacks the lubricity of gasoline. On conversions from the factory for new vehicles the hardened valve seats come as part of the package.

Most commercial users of propane fuel run what’s called a “hub-and-spoke operation” – in other words, the trucks or vans leave the yard or warehouse every morning and return to the same place every night. And the hub is where the refueling station is located.

(One point of clarification: Roush CleanTech makes these propane systems for Ford trucks and vans only; for other brands consult with a dealer or third party retrofitter. A list of those can be found at the end of this article.)

The fuel lines run up into a solid billet aluminum fuel rail. This is a single machined piece. It doesn’t have the seams and multiple pieces of a gasoline fuel rail, which might leak under propane’s pressurized system. Robust injectors and a screw-in design for the fuel filler neck (to maintain pressurization during fueling) round out the hardware spec sheet.

Roush CleanTech has also developed a fuel pressure control modulator that regulates the pressurization throughout. It backs off the fuel pressure in the injector at idle and clears out the fuel lines when the vehicle is not running. Roush is also one of only two companies that Ford allows to have access to their factory software codes. This enables them to do custom calibrations of the factory control module for better diagnostics and help make the propane engine management identical to gasoline.

Fuel tanks and range

Roush CleanTech designed its tanks in two sizes to make sure you get good range. For example, the Ford F-150 offers an underbed configuration that holds about 20 gallons and a larger in-bed tank with a 46-gallon capacity. At 11 to 12 mpg, that gives the smaller tank at least 220 miles of range, and the big tank can take you more than 500 miles before refueling.

This brings up the most important consideration in evaluating the suitability of propane for your fleet. Most commercial users of propane fuel run what’s called a “hub-and-spoke operation” – in other words, the trucks or vans leave the yard or warehouse every morning and return to the same place for every night. And the hub is where the refueling station is located.

That’s not to say you can’t get propane anywhere other than your own pump. There are more than 2,500 propane refueling stations across the country. For the locations of these go to www.drivealternatives.com, or www.afdc.energy.gov/afdc/locator/stations.

Maintenance

There are no additional service or maintenance steps to take with propane powered vehicles, and Thompson recommends you stick with the factory service intervals on things like oil, coolant and filter changes. What you may find, however, is that your oil stays in better shape longer with a propane engine. That’s because the lower carbon content of propane, means less soot accumulating in the oil, and soot levels are often the determining factor in oil life. You’ll also keep your spark plugs cleaner since there is less carbon buildup. And propane, as it changes from a liquid in the tank to a gas in your injectors, helps keep your engine cool, especially the intake valves.

The Texas Railroad Commission has reported a 50-percent reduction in maintenance costs from running propane as compared to gasoline in its vehicles. If you want to extend drain intervals, however, do so only with the blessing and advice of your truck or van dealer.

Natural gas vehicles worldwide

With just 122,000 natural gas vehicles currently, North America is far behind the rest of the world in their adoption of this resource. Here are some of the leaders:

Pakistan: 2.3 million

Argentina: 1.8 million

Iran: 1.7 million

Brazil: 1.6 million

India: 900,000

Environmental implications

The environmental community, once supportive of natural gas, has turned against it citing concerns over underground water pollution caused by the drilling method known as hydraulic fracturing or “fracking.” But given that the gas in these formations sits thousands of feet underground and most water sources are 100 feet deep, the issue remains debatable. In 2010 the Pennsylvania Department of Environmental Protection issued a report that said: “No groundwater pollution or disruption of underground sources of drinking water has been attributed to hydraulic fracturing of deep gas formations.”

Additional sources for propane conversion

www.ImpcoTechnologies.com

www.jasperengines.com

www.greenalternativesolutions.com

Otr tires – by the numbers

How to crack the codes for lower cost and longer-life tires

By Tom Jackson

Next to fuel and wages, tires are the biggest operating cost for heavy construction fleets.

Yet a surprising number of contractors care little about their tires as long as they’re round, black and rolling.

Such indifference is financial folly. The experts we talked to say there is an OTR tire shortage looming on the horizon, if not already here (see sidebar on page 54). And the last time this happened, 2005 to 2007, prices for some sizes of earthmover tires doubled and even tripled. Back then new machines shipped barefoot (without tires) to customers and trade shows, and some contractors got so desperate they bought machines at auction just for the tires.

If you want to keep working through this pending shortage and maximize your tire life and minimize costs you need to understand the science and nomenclature behind today’s off-the-road tires. There are a lot of numbers and codes and formulas to decipher, and to make it even more confusing there are industry wide codes and nomenclature and then there are manufacturer-specific designations.

The tires that come on new machines tend to be general purpose and not always the best tire for low cost per mile or hour. But when it comes to the second and subsequent sets of tires you can lower your tire cost per mile as a well-informed tire customer.

OTR categories

Here is what you need to know.

The use of these tires on the designated machines, however, is not necessarily cut and dried.

A L-5 design, Titan’s LDR 250 tire has the heavy tread and stiff sidewalls needed for a loader tire to survive in a harsh environment.

 “You see a lot of L-5 tires on graders in mine sites, because they’re exposed to sharp rocks as they’re grading the haul roads,” says Pete Kearney, ORT sales and marketing in the southeast for Titan International. “The reason most quarries and mines put L-5s on their graders is so they can put them on and forget about them. They’ll last forever unless you impact them and it’s pretty tough to impact an L-5 on a grader.”

Loader tires can be overkill for a grader in other applications though. In dirt, sand and gentler conditions, the extra protection is unnecessary. And loaders by their nature put extreme weight and stress on the front tires when the bucket is full. This demands a robust bead design and thick sidewalls. All this mass makes a tire that’s easy to heat up and slow to cool down. But heat is normally not a problem for L tires on loaders because loaders don’t go very fast or very far.

Double Coin’s L-5 REM9 is on E-4 tire that features a balance between rock and cut protection and traction.

Earthmover tires, by contrast, run at much higher speeds and aren’t built with the same mass and thickness that the loader tires receive. A beefy loader tire would quickly overheat on a speedy haul truck, plus the extra weight and rolling resistance of a loader tire would rob a truck of some of its carrying capacity. “You can move an E tire to a loader if you don’t over stress it, but you couldn’t move an L tire to an earthmover machine,” Kearney says.

Quarry face work generally needs an L-4 or L-5 tire, says Steve White, market segment manager, Michelin Earthmover Tires. They offer more wear life in high scrub applications and have more protection against impacts or punctures. They are also heavier, he says, so if the job doesn’t require the robust construction or tread depth, an L-2 or L-3 will be lighter and more fuel efficient. L-2 and L-3 tires, because of their more open tread designs will also give you more traction for crowding the pile, he says. Using an L-5 instead of an L-4 or L-3 in a sand and gravel application is a waste of money, White says. The tread on the beefier tires wears slowly and the casing would become fatigued before the tread wears out, especially if the tire goes through more than the normal number of deflection cycles.

In the earthmover category or E-service tires, E2 and E3 rated tires likewise have less tread than E4 and are used in higher speed applications. Their shallower tread depth and quicker wear is offset by their greater Ton Mile Per Hour (see below) rating and ability to move material more quickly.

On the E-service category, you don’t want to use a shallower E3 or E2 if the speed and distance don’t require it, White says. “By using an E4 where high speed is not needed, you will get more hours from the tire. On the other hand, using an E4 when a higher speed E3 or E2 is required will mean having to lower the transport speed to stay within the capability of the tire. “If you don’t you will overheat and cook your valuable asset,” he says.

Examples like these show the importance of picking the correct tire for the application. If the tire is not robust enough it may be damaged before the tread wears out. If the tread is too robust, the casing may give out, leaving you with a lot of used tread – and tread that’s robbed you of some fuel economy as well. White says the key is to understand your conditions and the tire options and tradeoffs and then consult with a manufacturer’s representative or tire dealer to help make the proper choice.

Ton Mile Per Hour rating

A critical formula for selecting and managing tires on large quarry and mining trucks and scrapers is the Tons Mile Per Hour or TMPH. The mathematical formula for figuring TMPH is below, but simply put it is the average tire load times the average speed for the shift.

“TMPH is an expression of the working capacity of a tire and is a function of the maximum allowed internal operating temperature of a tire,” says White. “If you are exceeding this limit you are overheating a tire which could lead to catastrophic or premature failure.”

The relationship of speed to heat is easy enough to understand – the faster you go the hotter your tires get. But load plays a big role in heat generation as well. The sidewalls on an overloaded tire flex more than normal and flexing adds heat – just like when you bend a coat hanger, says Roger Best, senior field engineer Bridgestone Commercial Solutions Group. Bend it once – no difference. Bend it repeatedly and it becomes warm.

Every tire design will have a maximum allowable TMPH. “A bias OTR tire that contains multiple layers of fabric has a tendency to build up more heat,” says Aaron Murphy, vice president, CMA. “The radial OTR runs cooler due to the single layer of steel cord wire.”

Big OTR tires have a TMPH rating manufacturers publish, but it’s up to you the contractor or fleet manager to calculate the TMPH of your operation to make sure the work your trucks are doing doesn’t exceed the TMPH limit of the tires. And more importantly, that number can change, and change frequently.

Bridgestone’s 45/65-45 DuraLoad tire for large loaders has a flatter crown radius for a more even footprint and is designed for easier mounting. It’s available in L-4, L-5 and L-5S tread types.

“As your operation grows, your weights, speeds and distance to the crusher are going to change,” Kearney says. When those change, the TMPH changes also. “Staying on top of that is usually up to the tire dealer and manufacturer, but it can change daily,” he says. But a good fleet manager will keep a close eye on these variables and understand if the haul distance increases, the speed or weight of the loads may have to come down in order to stay under that maximum TMPH number for the tire. And conversely, a shorter haul may allow you to increase loads or speeds.

With its non-directional and center rib this REM 11 tire from Double Coin is designed for cut and chip resistance.

“It’s not very hard to get in your truck and re-do the cycle times and weights to find the TMPH,” Kearney says. “And if you find that the tires fall outside the TMPH or that something has changed, you can go to the superintendent and say, ‘Look, is it possible to slow the trucks down, because this is what’s going to happen if we don’t.’”

Managing tire maintenance and inventory is essential before a shortage occurs.

White adds that overly tight curves on haul roads can also affect tire loading and TMPH considerations. “This overloads the outside wheel positions, particularly in the front,” he says. This can be corrected by slowing down in the corners and maintaining proper speeds or by banking the corner more gradually. Steep grades also affect tire loading, overloading the rear tires going uphill and the front tires going downhill. “We prefer to see maximum grades of about 6 percent and no more than 8 percent,” he says.

Likewise pay attention to your truck’s suspension. A suspension problem may result in uneven tire loading even though material in the bed of the truck is distributed uniformly, White says.

There are four service categories of tires for construction machines. These are indicated by the following industry-wide, single-letter designations: E, L, G, and C; followed by a number indicating tread type.

E = Earthmover, but more specifically it means tires for end dumps, scrapers and articulated trucks. These are designed for speeds up to 30 mph and round trip haul distances up to five miles.

L = Loader/dozer tires. Built for a top speed of 5 mph and travel distances no more than 250 feet, one-way load and dump.

G = Grader tires. Designed for unlimited distance and speeds no greater than 25 mph.

C = Compactor tires. Includes both pneumatic and solid tires for use on pavers and compactors.

Tread types are indicated by numbers 1 through 5. Higher numbers indicate more tread area and less void or cavity around the tread and a thicker tread. Lower numbers give you more traction, higher numbers more protection. There is also a 7 designation in the earthmover service category which is a flotation tire (but doesn’t follow the same tread depth criteria), and an S designation in compactor tires.

S = Smooth.

1 = Rib: 100 percent tread depth

2 = Traction: 100 percent tread depth

3 = Rock: 100 percent tread depth

4 = Rock deep tread: 150 percent tread depth

5 = Rock extra deep tread: 250 percent tread depth

7 = Flotation tire

TMPH calculations

To get the average tire load, multiply the loaded and unloaded weight per tire in tons of the truck and divide by two. To get the average speed, multiply the miles per trip times the number of trips and divide this by total hours in the shift. Or to put it into an equation:

Empty tire weight + loaded tire weight x Average shift speed x number trips per shift

2 Hours per shift

For example you have a truck that puts 10 tons on each tire when it’s unloaded and 17 tons on each tire when it’s loaded and you drive it 9 miles per hour, 15 trips per day over an 8-hour shift. Then the math looks like this:

10 tons + 17 tons = 13.5 tons average weight

2

9 mph x 15 trips = 16.9 mph average mph

8 hours

13.5 tons average weight x 16.9 mph average mph = 228 tons mile per hour (TMPH)

To prevent heat problems you should have a TMPH rating of 228 or higher, and this should be the minimum for the highest rated tire on the truck. Also note that the formula doesn’t work for tires loaded more than 20 percent above their rated capacity or for haul distances longer than 20 miles.

What kind of rubber?

Another important consideration is what tire manufacturers call the rubber compounding. In the chemical composition of their rubber manufacturers tweak the formulas to make either a standard compound, a cut-resistant, abrasion-resistant or a heat-resistant compound. And some compounds will be a mixture of these properties.

“OTR tires are application specific, so these compounds are another way the manufacturer pursues having the correct tire in the correct environment to ensure optimum performance and cost per hour, mile or ton,” says CMA’s Aaron Murphy.

There are no industry-wide standards for designating compound types – some use letters, some use numbers and some use both – so you’ll have to ask.

“If you’re in a rough application – slow haul, short distance – the best thing is a cut-resistant tire,” Bridgestone’s Roger Best says. “As long as you don’t fatigue the tire, it should match life for wear. If you’re in a high-speed haul with a sandy surface, a heat-resistant tire would be best because it on a sandy surface you’re not wearing very much.”

What heat does to tires

Heat will destroy any tire for one very simple reason. Rubber is vulcanized or cured, if you will, at approximately 300 degrees Fahrenheit. Once cured rubber starts getting close to that temperature it reverts back to its natural state (depending on the chemical makeup), which Bridgestones’s Roger Best says is a powdery mess. “It will create gasses that will

Running underinflated is often the cause of heat problems, Best says. “It’s basically the same as overloading.”

bulge out the sidewall and the tire will usually split in the shoulder to vent those gasses. If it’s extreme heat it may separate the belts from the tread package. And once there is separation, it’s not going to go away. It’s going to get worse. If you heat seperate a tire, the tread’s going to come off the casing.”

Running underinflated is often the cause of heat problems, Best says. “It’s basically the same as overloading.”

The new tire shortage

All the tire companies we’ve talked to tell us that we’re either in an OTR tire shortage now, or predict that we will be in one soon. Highway haul truck tires are more affected now than OTR tires, but the situation for OTR tires is growing worse.

The last time this happened (2005 to 2007) the shortage was caused by demand – the developing world, the wars in the middle east and the booming U.S. economy. This time, the experts say, the shortage is being driven by a limited supply of natural rubber from Malaysia.

“We’re starting to get phone calls from the OEMs and once that happens you know something’s coming.”

“Things are getting tighter,” Titan’s Pete Kearney says. “We’re starting to get phone calls from the OEMs and once that happens you know something’s coming. You can get 2700/49s right now, but you’re going to have to wait six to eight weeks for them. A month from now you may be waiting 12 to 16 weeks.”

The smart move for equipment managers in the face of this looming shortage is to build inventory and to maximize the life and cost effectiveness of the tires you have now. Partner with your dealer to make sure you’ve got the right tire and the right cost per hour or ton. Dealers can also set you up with tire tracking software that can give you a history of your tire successes and failures and apply that knowledge to make better choices in the future.

And last but not least maintain a rigorous air pressure monitoring system. “If you’re letting your air pressure drop 10 percent, you may be losing 20 percent of your tire life,” Best says. “Don’t buy a premium tire and then neglect the air pressure so that it doesn’t last any longer than a standard tire.”

DPF service intervals are few and far between – but stay on your toes; the filters work so well they sometimes mask serious engine problems

By Tom Jackson

If you’ve bought a new diesel engine truck since 2007 or in some cases a new piece of equipment this year, there may be a new service interval to add to your preventive maintenance schedules.

Dirty exhaust enters the DPF, and soot is trapped on the coated ceramic honeycomb

 The new service item is diesel particulate filter maintenance. The DPF is an exhaust filter that helps these engines meet tough new emissions requirements. All heavy-duty diesel trucks engines built since 2007 come with a DPF. And many off-road equipment engines starting this year will come equipped with the device – especially those in the higher horsepower bands.

DPFs capture soot or particulate matter before it has a chance to exit the exhaust stack.

In fact, soot levels have been cut more than more than 99 percent in 10 years, thanks in large part to the DPF. But there’s a Catch-22 in this good news. The DPF is so good at scrubbing particulate emissions from your exhaust stacks that it can conceal the visible smoke that used to be a tell-tale sign of engine problems.

To help you understand the how the maintenance requirements have changed, let’s first look at how a DPF works.

The technology

A DPF is much like a catalytic converter on a car. It is a large, ceramic based filter coated with precious metal catalysts and encased in a steel canister plumbed into your exhaust system.

When soot laden exhaust enters the DPF, it is trapped on the surface of the filter. The soot is quickly burned off under normal operating temperatures – a process the industry calls passive regeneration. However, if the operating temps don’t get high enough, which may occur in cold temperatures, stop-and-start operations or when idling for long periods of time, a quick burst of fuel from a “seventh” fuel injector into the DPF will raise temperatures and burn off any soot accumulations. This is sometimes referred to as active regeneration. The terms active and passive are a little misleading in that the operator doesn’t actually do anything in either case. Sensors in the exhaust system tell it when active regeneration is needed and it takes place automatically.

Eventually, however, trace amounts of ash from the combustion of lube oil will collect on the interior surfaces of your DPF. Ash doesn’t burn, so it has to be mechanically cleaned out when it reaches the point where it impedes exhaust backpressure. And once the filter reaches that state, a backpressure light will come on indicating that DPF cleaning is due.

Using the new low-ash oil formulations, designated with an American Petroleum Institute CJ-4 label, is imperative with these engines. You should also be using ultra low sulfur diesel fuel in any truck or machine equipped with a DPF as the higher sulfur content in low sulfur diesel can contaminate the precious metal (or catalyst) coatings on the filter honeycomb. This should not be a problem in the United States since LSD fuel has been phased out, but it could impact your ability to use or sell the truck or equipment to a buyer in another country with higher diesel sulfur levels.

Smoky diagnosis

There is no doubt that DPFs work as advertised, and have had a huge positive impact on making diesels run cleaner. But if there is one downside it is that they may mask serious engine problems that used to be easy to diagnose. On older engines, when you saw white or black smoke streaming from your exhaust stacks, you knew you had a blown turbo, a faulty injector, worn rings or coolant leaking into the cylinders or similar issues. But today’s DPFs will let little if any of that smoke escape.

“That is a general concern for the entire industry,” says Rakesh Aneja, senior manager, product engineering at Daimler/Detroit Diesel. “Exhaust smoke is a classic indicator that something needs to be retuned, or maintenance work needs to be done. Now the filter is masking that and the diagnoses become more challenging. It may lead to aftertreatment failures if it is a high smoke condition and loading up the filter more and more.”

“When there are engine component failures, we don’t find out anymore by looking at the smoke,” says Fred Schmidt, business development director in the Donaldson Emissions Group. “We find out by the backpressure light activating.”

These kinds of engine problems should trip the backpressure warning light in a short period of time – but any time the light comes on drivers or operators should immediately notify the shop. Normal plugging of a DPF with ash is not an emergency situation; you can still drive or operate the equipment for a few days and suffer nothing more than a small fuel economy penalty, Aneja says. But if the plugging is caused by engine component failures you could be throwing a lot more than soot or ash into the filter and this kind of contamination could quickly ruin the DPF.

“In effect, the DPF system has become a kind of engine warning system that something has gone wrong,” Schmidt says.

Rigorous oil sampling can help, but may not detect every potential threat to the DPF, Aneja says. The key to preventing engine component problems from cascading into your DPF is to stay on top of your overall engine maintenance. New engine diagnostic programs from the manufacturers can help you spot these kinds of problems before they reach the critical stage, he says.

DPF cleaning and maintenance

The process of cleaning the DPF involves removing it and vacuuming or flushing out the ash, typically followed by a heat treatment or baking to incinerate any hard-to-reach particulate matter. Most manufacturers we talked to will take out your old DPF, put in a new one and give you a core credit for the old.

Most of the DPF cleaning is being handled by the truck dealerships. DPF cleaning equipment can be expensive for small fleets, as much as $80,000. “We have seen fleets purchase the recommended equipment, but the payoff will take a long time,” says Ed Saxman, Volvo’s powertrain product manager.

But there are a lot of variations in the cleaning systems and procedures, and DPF cleaning machines are offered for sale direct to fleets by different manufacturers. For example, Donaldson not only makes DPFs, but sells cleaning units to fleet customers. The Donaldson system costs approximately $20,000, Schmidt says, and achieves a one year payback for customers who anticipate doing more than 50 to 75 cleanings a year.

If you’re not doing your own DPF cleaning the service typically costs range from $250 to $700. That may sound like a lot, but keep in mind that the EPA required manufacturers to design their on-road DPFs to go at least 250,000 miles between cleanings.

DPFs are heavy enough to require a hoist to remove them from above or a jack to secure them if removed from below. The filter media itself could crack if dropped. Procedures for this work and warranty considerations will vary between different manufacturers so make sure you follow the OEM recommended guidelines.

DPF service intervals

Now that the truck engine manufacturers have had three years of results using DPFs, they say their engines are having no trouble exceeding the EPA’s 250,000 mile requirement. According to David McKenna, director of powertrain sales and marketing at Mack Trucks, the actual results their trucks have experienced is closer to 400,000 miles between service intervals.

Aneja says the cleaning intervals will vary according to how hard the engine works and how much oil is consumed. “For on highway truck applications that’s 300,000 to 400,000 miles, approximately,” he says. “But that’s not a fixed trigger. It depends on the duty cycle.” With today’s on-road DPFs pushing 400,000 miles between service intervals the expectation is that you should only need one DPF service procedure with a new or reman/cleaned DPF installed during the life of the engine, he says. “The customers wanted only one cleaning cycle in the life of the truck,” he says.

DPF maintenance for off-road is coming

Not every Tier 4 Interim engine will need a DPF. Most manufacturers worked hard to tweak engine parameters to avoid having to add new hardware. In the lower horsepower bands, many have been able to meet the emissions regulations with an oxidation catalyst that will last the life of the engine and never need maintenance – so-called “fit and forget” components.

For off-road engines, the EPA mandates the DPF must go at least 4,500 hours between cleanouts for engines 174 to 750 horsepower. Engines 75 to 173 horsepower must meet a minimum DPF service interval of 3,000 hours. Most manufacturers say their engines will exceed those requirements. Given that those hour figures represent several years of operation and that Tier 4 Interim standards just came due in January for engines above 174 horsepower, it’s still too early to tell. But if the on-road experience with DPFs is any indicator, the off-road engines should have no trouble meeting their target minimum hour levels for ash cleanout.

For those larger off-highway engines that do require DPFs, the technology, maintenance and ash cleaning will be essentially the same as for on-highway, says Kevan Browne at Cummins. The main difference between on- and off-road DPFs, he says, is the off-road versions will be built to withstand high shock loading and vibration tolerance, and to have more flexibility with installation configurations.

Since they’re still a couple years away, the service procedures for off-road DPFs have not been finalized by most dealers. Many talk of having an exchange program and core credits similar to those for on-road engines.

Note, however, that neglecting your air and fuel filters, cooling system, or oil drain intervals, as well as the previously mentioned engine component failure problems, can lead to excessive soot generation and shorten your DPF service intervals. “People used to be able to operate a diesel engine in a degraded state, but not anymore,” says Schmidt. “When that warning light comes on you need to take action more quickly.”

Whether you have one machine or thousands, online reports beat paper anytime.

By Tom Jackson

The fundamentals of oil analysis haven’t changed much over the years, but in the past decade the emergence of online reporting of oil analysis results has given fleet managers a great set of tools to do more, learn more and profit more from the reports.

Procedures for drawing the sample haven’t changed but online reporting of results can change the way you do maintenance.

Best of all for companies with time-sensitive maintenance schedules, you can get your results fast – especially critical alerts. “You’re getting data at the speed of light, vs. the mailman,” says Mark Betner, heavy duty motor oil manager at Citgo.

Fast results

Prior to online oil analysis reporting, it could take three or more days to get results back, after the tests were completed. Online reports eliminate that wait.

“Many of our customers schedule maintenance around their sampling,” says Mark Minges, chief operating officer at Polaris Labs. The technicians can pull a sample just prior to the machine coming into the shop for preventive maintenance and get the oil analysis results online from us within 24 hours of the lab finishing the tests – soon enough to take care of any problems that might arise while the machine is still in the shop.” This beats sending the machine back out only to recall it a few days later because it took a week to get the paper results to arrive by mail.

Critical vs. normal

Separating the critical results from those less urgent is another benefit. Most of the providers we spoke to allow you to customize your reports so that you can get an instant e-mail, text message, phone call or fax when your results show serious problems.

Your lab or lube provider will set you up with all the supplies you need to get started taking samples.

“Most customers don’t want an e-mail if there is nothing wrong with it,” says Minges. “They just want to deal with the ones that may require maintenance. To view all the normal reports or those that are flagged for observation they can log onto our website anytime and view those as well.”

Alerts and critical issues can be communicated to more than just one person, email address, phone or digital device. “A lot of people carry a phone or Blackberry on the job today, and this is an opportunity, if it is a critical issue, to see it right away,” says Len Badal, Chevron commercial sector manager. “If they’re out on the jobsite they can shut the equipment down immediately to avoid further damage.”

Predictive maintenance

“The advantage to the customer is it gives him a predictive ability,” says Ron LeBlanc Sr., senior technical advisor at Petro Canada America Lubricants. “You can look at a piece of equipment over its lifetime and know when to rebuild it – not on an emergency basis, but on a scheduled basis.”

Taking a clean sample helps make results more accurate.

This predictive ability can transform your oil analysis program from a simple warning system to a powerful diagnostic tool. “With the graphing abilities of an online oil analysis program you can cue up reports on wear, chart the trends and quickly sort out the machines that may not be performing up to the norm,” LeBlanc says.

“We have a feature called summary analysis that will allow you to take any data oil analysis provides and click on that data and create a maintenance report card,” Betner says. “It tells you the percentage of time that you’re seeing problems in specific areas. You can set it up by engine type to see of one brand of engine is showing more problems than others and avoid inherent issues that may exist in some equipment types. If you have more than one maintenance facility, you can see how each facility is doing relative to another. We have fleet managers who actually reward their employees based on this type of data,” he says.

“A person can log in and basically take the data and do what they want with it,” says Badal. “They can pick and choose what they want and chart trends very easily. They can customize reports and the things they feel are important to them.” As an example Badal cites contractors who chart the particle size in their hydraulic fluid. Over time these particles will grow in number and when they reach a certain point they can do a lot of expensive damage to your hydraulic system. But by charting the growth of these particles the maintenance manager can choose the optimum point to replace or clean the hydraulic fluid, saving himself an expensive repair, and not waste money on redundant or unneeded maintenance either.

In most cases you can also sync your online oil analysis reports with other maintenance software you use to manage your fleet. Because there are dozens of different maintenance programs these sometimes have to be done on a case-by-case basis, but the process is not difficult.

Getting started

If you’re not already doing oil analysis, the way to get started is to contact your lube supplier or a laboratory such as Polaris or your lube supplier. Some lube oil suppliers have their own labs, others will refer you to a lab. The lab or supplier will set you up with the necessary equipment, sample bottles and preprinted labels. Most experts also recommend you put a sampling valve on your engine. These allow you drain off small amounts of oil cleanly without contaminating the sample.

Analyzing oil sample results online enables you to predict and schedule maintenance.

Look for quality in a lab or oil analysis provider. The ASTM has standards for the labs and the lab should be certified, says Badal. Also ask about cost, but don’t go cheap. “If somebody is offering you $2 samples, you’re going to get what you pay for,” Badal says. The average cost for a basic oil sample runs $8 to $12, but for detailed or certain specific tests you may need to pay up to $50.

Your lab or provider should also offer training to you and your maintenance crews or anybody who pulls the samples. “There has been more apathy created about oil analysis by not getting started right. You need to seek out a provider who will work with you and who knows what they’re doing,” Betner says. “Too often oil analysis is used as a sales add-on,” he says. You need to find a provider who will help you set up the program the right way, tell you how often to sample, how to read the reports, the best practices and how to follow up on the reports. And it’s not enough to do it just the first time. There is turnover in people, there are changes in equipment, and there are new things we are learning about oil analysis all the time. It’s a dynamic thing. Too many fleets say ‘I don’t think it really works for me,’ and that’s probably a result of not getting off to a good start and understanding how to make it work.”

Who needs it?

Oil sampling is the rule for most managers of large fleets. And that includes not only engine lube oil sampling but hydraulic fluid, coolant, transmissions, final drives and many other machine compartments.

But what about the guy with just one truck and a backhoe, or just a handful of machines? Is all this really necessary for the small operator?

“If you have just one machine, then that machine is your business,” Betner says. “If that machine goes down, you’ve lost your whole business. There is every reason in the world to take every preventive maintenance tool you can use because if that machine goes down you’re not generating revenue, period.”

Big and small

You don’t have to restrict oil sampling to just heavy, off-road diesel engines either. Sampling is a good tool for every kind of machine, says LeBlanc. “I am seeing more interest in oil sampling now than ever before,” he says. “In this economy it’s just as important on a $2,000 piece of equipment as it is on a $500,000 piece of equipment. People need to get a longer life out of their equipment and they are sampling on a frequency to help them predict the life of that equipment.”

In the last decade all the emissions-related changes to on-road diesel engines, EGR, SCR, plus three new American Petroleum Institute oil categories make an even stronger case for sampling, LeBlanc says. Plus the most recent crop of diesel engine pickup trucks are doing more work with smaller engines, putting a lot of strain on the engines and oil. These are now ¾ and 1-ton pickups routinely pulling 15,000 pound/5th wheel trailers. “It’s vitally important that you do oil sampling here because the demands on engines – particularly since 2007 – have really gone up,” he says.

Oil analysis can also help in diagnosing a machine or truck that has problems that need further investigation, Minges says. Also remember that oil sampling, can help decided warranty issues in your favor as well. “We get samples from units that have failed – typically from insurance or law firms if there is potential litigation,” Minges says. EW

Training, maintenance and software pay big dividends

By Tom Jackson

After two years of trade school a good mechanic will know a lot about engines, hydraulics and transmissions. But where do they go to learn about tires?

Regular visual and air pressure checks by operators and tire technicians are key to maximizing the longevity of your tires and preventing unplanned downtime.

In most cases – nowhere. Tires aren’t taught in vocational schools, and given what they cost you, that’s unfortunate. After fuel and operator wages, tires are often the largest single operating cost for a piece of equipment. What’s more, having the right tires in good condition will boost productivity and fuel economy, reduce downtime and improve safety.

To realize these benefits you need a tire program with monitoring, maintenance, and in many cases tracking software. But rather than take the time to become a tire expert yourself you can usually tap into resources provided by your tire dealer.

Sign up for tracking

Most of your major tire vendors now offer tire tracking software. “We track everything about the tires from the cradle to the grave,” says Chris Rhoades, TreadStat product manager, Bridgestone Americas Tire Operations, off road division. “Tire performance, tread depths, air pressure, rotation schedules, retreads, visual comments, percent utilization – everything up to their disposition as scrap. With the tracking software you can drill down using any metric.”

A tire tracking software program compiles data on tire use, maintenance and condition and helps you establish accurate costs and plan for inventory and replacement schedules.

And good recordkeeping brings numerous benefits, short and long term. “If you know why your tires are failing early you can put in counter measures,” Rhoades says. “If you are experiencing a lot of sidewall cuts you know that your haul roads aren’t wide enough. If you’re getting a lot of tread cuts, the dumping and loading areas probably need to be cleaner and better maintained.”

Longer term, tracking software lets you look at inventory and asset reports from month to month and generate budgets and plan acquisitions, Rhoades says. By charting the actual life of the tires you get an accurate idea of your expected tire life and your true tire costs. You can also plan tire purchases and replacement schedules to avoid unexpected downtime or having to interrupt operations in the middle of your busy season.

Software can also help you compare cost and value. A more expensive, high quality tire will usually prove the best value in the long run. But if you’re running in harsh applications where the tires are more often destroyed than worn out, then a less expensive model may be a more cost effective solution.

Some jobs are tougher on tires than others, and with good records and damage documentation a contractor puts himself in a better position for accurate bids going forward, says Steve White, Michelin earthmover market segment manager – construction.

When operators are trained in the value of clean loading areas, their tires are less likely to suffer from rock cuts and early failure.

Contractors with just a handful of machines may not need the sophistication of tire tracking software. But don’t fool yourself, Rhoades says. “A lot of people think they can hold more stuff in their head than they really can,” he says. “If you ask them how their tire performance is they’ll answer ‘great,’ but ask them if they know their cost per hour or what percentage of their tires came out early and they don’t know. Everybody assumes they’re doing OK, but when you actually have the data, you can begin to start improving it.”

Data entry on tire tracking programs can be done by anyone. Rhoades says. But about 90 percent of the time it’s done by the dealer. If your dealer is servicing the tires, his technician can record the data on each service call and keep records more accurately than can operators or your mechanics.

Tire maintenance

“The better a contractor’s tire maintenance program, the more they will maximize their cost per hour.” says Pete Kearney, OTR sales and marketing, southeast for Titan International.

Contracting your tire inspections and service to your tire vendor frees up you and your operators to concentrate on the job at hand.

Periodic maintenance should include air pressure checks, measuring tread depth and visual inspections of the tires for damage and inspections to make sure the tires are all the same diameter. Air pressure checks are the number one item on every tire expert’s list. “Running under-inflated or over-inflated is the death of any tire,” Kearny says. “It will ruin the integrity of the casing.”

A contractor should have his operators trained and checking the air pressures regularly rather than wait for the tire vendor’s service tech. Proper pressure allows the tire to operate more correctly for traction and heat generation, says White. It allows the tire to more efficiently roll over obstacles and conserves fuel and tread life. A contractor should have his operators trained for visual inspections of air pressure between his regular pressure checks by either his maintenance crew or the tire vendor. This could give a quick indication of any issues.

Part of this training should include teaching operators and supervisors not to exceed a machine’s limits, says White. This means maintaining the proper speeds rather than racing to the dump site, not putting too much material in the bucket, or adding sideboards to a truck to allow overloading. These things are often done to increase productivity, but the equipment and tire damage and downtime that result can cost more than the increased productivity is worth.

Make sure operators know to check pressures with the tire cold, and for most earthmovers, with a big bore pressure gauge. They should also know that different loads require different tire pressures. Most tire experts advise setting up an air pressure maintenance program, with all these elements in it and all your operators and technicians informed and onboard.

“The operators are the key factor in both production and tire performance,” says Aaron Murphy, vice president at Double Coin Tire. “Many companies offer incentives to keep operators motivated to maintain tires and equipment. Operators play an important role in making sure haul roads and pit areas are maintained, which eliminates premature failure due to cuts.”

Sub out the big stuff

Aside from the operator’s daily checks, when it comes to service and in-depth inspections and maintenance consider partnering with your tire vendors. The vendors’ tire service technicians know more about tires than mechanics, and tire service trucks are specialized pieces of equipment that don’t make sense for most contractors. By contracting with your dealer for tire service you can concentrate on running your business, and your fleet technicians can focus on mechanical maintenance and repair.

There are also safety considerations, especially with OTR tires that can require air pressures as high as 100 psi. White says he has talked with fleet managers who after seeing tire explosions were hesitant to have their guys working on tires.

The level of service you need depends on how many machines you have and how hard you work the tires. Regular inspections and monitoring should be a part of this service. For a small contractor this could be quarterly or twice a year for all of your machines. Larger fleets may need to schedule tire service on different portions of their fleet as often as once a month.

Another benefit to subbing out the service is that a tire technician can do his work in the evenings or Saturdays or Sundays to keep from slowing down a contractor’s busy production schedule, says Roger Best, senior field engineer at Bridgestone Americas, Off Road Tires.

Having an expert eye on your tires may come in handy if you work at or are bidding on jobs at refineries, chemical plants or anywhere that a tire explosion could cause a destructive chain of events, Best says. “A lot of these places will only let you run new tires, no retreads or repaired tires, or anything with the potential to fail,” he says. And there are machines such as telehandlers that may need more frequent tire inspections as a blowout on one of these could endanger the safety or lives of workers in a platform or near the material being lifted.

Take time for training

“The mobile equipment superintendent is educated on every aspect of equipment except the tires,” says Kearny. “So a lot of the larger contractor companies are partnering with their tire companies and doing tire training,” he says.

“We bring them in and talk to them about many of the aspects of tires,” says White. “It’s generic training, for two or three days. We often bring in a customer with his dealer. We talk about the importance of air pressure, maintenance, inspections and how to look for damage. We have tires with specific damages we show them and we ask them to guess how the damage occurred.”

Two or three days of tire training won’t make you an expert, but it will give you the fundamentals you need to be a better tire consumer and knowledge you can take back to operators and mechanics to develop a tire program. You can also bring back a lot of good tire safety material for your safety meetings, Best says. “We push for at least a once a month talk on tire safety,” he says. It’s not just about making tires run longer, but run safer too.”

Retread Solution

In any OTR tire program you should seriously consider retreading. It depends on the application but many companies remove tires with approximately 15 to 20 percent of the tread remaining to have them retreaded, says Aaron Murphy, vice president, Double Coin Tire.

Retreads can often give you the same performance as a new tire at approximately half the cost. But certain types of damage and wear will render a tire incapable of being retreaded. Consult with your tire dealer to see how you can save money with retreads.

Destructively different diameters

With the thick treads found on may earthmoving machines it’s not uncommon for the tires to slowly wear down to different diameters. The equipment OEMs have specs as to how much inequality in tire diameter is allowable. But running a machine beyond those specs can damage axles, transmissions and driveline components. Professional tire technicians are best equipped to measure and evaluate tire diameters in these situations.

Letting the air out

A 10 percent difference in tire pressure over or under the manufacturers recommended pressure can result in a 20 percent decrease in tire life.