Cat will use two main strategies in its approach to supporting Tier 4 Cat machines sold in lower regulated counties, says Mary Roethler, Caterpillar’s Tier 4 Dealer Readiness manager.
Tier 4 machines, whether Interim or Final, require ultra low sulfur diesel, which complicates the sale of used Tier 4 machines into countries that do not sell ULSD.
For machines in the 75-175 horsepower range, Cat is training and tooling their dealers in lower regulated countries to take off the emissions aftertreatment. Removal will decertify the machine for sale in highly regulated countries such as the United States.
But for machines above 175 horsepower, Cat says the machine’s regeneration system uses a combination of chemicals and heat to take care of the higher levels of sulfur in the fuel, and thus, no modification is needed.
That means that machines in this higher horsepower size classification—since they are not decertified—can be sold back into the North American market and other highly regulated areas.
“This issue is complicated because of the differing regulations in each country,” Roethler says. Cat’s current Tier 4 machine population is 82,000-plus machines, and many of those have more than 9,000 hours, making them candidates for the used market. “Through our ProductLink telematics, we’re watching these machines, tracking where they go and the typical hours at which they are sold,” she says. For example, excavators are popular in Mexico.
As Cat envisions it, for 75 to 175 horsepower machines, Cat dealers in a lower regulated country will take off the aftertreatment systems, since federal regulations prevent U.S. dealers from doing this procedure. The decertification process will be available from these non-U.S. Cat dealers next year; the cost of this process has not yet been announced.
Because of the high integration of fuel management and electronics with the aftertreatment system, Cat says this process will have to be done by a Cat dealer.
Buyers in lower regulated countries will need to be educated about the extra cost of taking off the aftertreatment system on used Tier 4 machines.
Cat also reviewed its strategy for Tier 4 Final engines. “The Tier 4 Interim journey was the most challenging new product introduction in our history,” says Doug Mihelick, commercial manager of Cat Machine Engine & Components. The challenges required by these engine emission regulations included developing and producing 350-plus products and meeting multiple emissions requirements that involved several new technologies.
“Now we get to do it all over again with Tier 4 Final,” Mihelick says, “and at a rate that matches our Tier 4 Interim pace of seven new models a month.” Tier 4 Final regulations, aimed at reducing oxides of nitrogen coming out of the exhaust, start to go into effect this January.
Despite the challenges, Mihelick calls the Tier 4 Interim implementation—which has been in place the past three years—a “very successful new product introduction.” Cat says it has 82,000 Tier 4 Interim powered products in the field with 42 million-plus operating hours in North America, Europe, Australia and New Zealand, as tracked by ProductLink. “Customer reaction has ranged from between pleasantly surprised to delighted,” Mihelick says.
Earlier this week, Ed Rapp, Cat group president, said the company had invested $7 billion to get from Tier 4 Interim to Tier 4 Final. “Our dealers have stepped up with training and tooling investments for Tier 4 Final machines,” Mihelick says, reporting that these machines are now in production and “dealers are ready right now.”
There are now more than 300 Tier 4 Final “field follow” machines—a term used by Cat for pre-production machines demoed in the dirt at customer sites. Using a Selective Catalytic Reduction aftertreatment exhaust system that requires the used of Diesel Emission Fluid, or DEF, these machines have logged more than 300,000 hours, some operating in minus 55 degree Fahrenheit temperatures at high altitudes plowing snow.
The cold weather experiments are especially critical in learning how to deal
with DEF, which is 67.5 percent de-ionzed water, and freezes at -12 degrees Fahrenheit. The heavy DEF tank contains a heating element and heated fuel lines. Emissions regulations require that the DEF be converted from a solid block of ice to usable fluid within 70 minutes, which Cat says can easily be met.
Cat is recommending contractors make topping up the DEF tank—which they’ve located near the fuel tank fill on many machines—a regular part of fueling. To help prevent a fluid going into the wrong tank, the fill necks of the diesel fill and DEF fill are different sizes, and the DEF fill has a blue cap, plus carries a warning not to fill with anything other than DEF. If diesel does get into the DEF tank, it may have to be drained, depending on the level of contamination.
New Final engine maintenance practices revolve primarily around the storage of DEF, which will be available for Cat machines from Cat dealers and other suppliers, including truck stops and automotive parts stores. DEF needs to be stored in a cool, dry, well-ventilated area away from direct sunlight. DEF will degrade over time, depending on how long it is exposed to high temperatures and shelf life.
Another maintenance concern is keeping the DEF clean of debris. “This will be an off-highway industry challenge, since the on-highway SCR engines don’t deal with the large amount of dirt and other debris that off-highway engines do,” Mihelick says. “Filtration will be one obvious solution,” he says, but others may be required as more hours are logged on DEF-equipped machines.
If a machine owner is going from a Tier 4 Interim to a Tier 4 Final machine, the operational differences will be slight, Mihelick says. “With an Interim machine, the regeneration device was the primary way to remove soot,” Mihelick says. “On a Final machine, you’ll be using the regeneration device much less. In fact, some machines will never have to regen.” Because of this, the soot gauge on the dash has been replaced with a DEF-level gauge. A warning system will issue progressive alerts if the DEF tank needs refilling. If the DEF level is too low, the engine will derate until the DEF tank is refilled.
On Final machines, after a machine is turned off, an electric system purges DEF from all lines back into the tank, an operation invisible to the operator. In the unlikely event of a high-temperature shut down, the machine will automatically continue to idle in order to cool down the DEF to an acceptable shutdown temperature.