Owning and Operating Costs

Compact excavators appeal to almost everybody: electricians, plumbers, landscapers, foundation contractors and even earthmoving companies that need a maneuverable detail machine for tight spaces.

And unlike more massive machines that have to be traded out on a schedule to avoid major component repairs or price depreciation, compact excavators hold their value and can deliver years of service without expensive repairs.

To get a clearer picture of what the owning and operating costs of a new compact excavator would be we turned to Marty Miller, product manager for excavators and Tom Connor, product specialist for excavators at Bobcat. They recommended we study the company’s new E35 compact excavator as its size class, 3 to 4 metric tons, comprises about 40 percent of all compact excavator sales.

Two lifecycles
A compact excavator in the 3- to 4-metric-ton category will typically see 350 to 400 hours of use a year as what Miller describes as a “primary” machine. A typical life span as a primary machine is four to five years. To calculate our numbers we put down 400 hours per year for five years for a total of 2,000 hours.

At 2,000 hours the contractor is likely to consider this a secondary machine, one that’s used as a backup and not every day. The condition of the undercarriage and the work group (boom and arm linkages) will be the major consideration, Connor says. Both can be rebuilt, he adds, and this is something many customers can do on their own. “In some cases it’s a winter project,” he says. As a secondary machine, a compact excavator won’t see much more than 100 or 200 hours of use in a year.

In a lot of bigger machines, the wear on the engine or the hydraulics determines the lifecycle. But with good maintenance and care, excavators in this size range can go 5,000 to 6,000 hours before needing rebuilds. This, combined with the fact that as a secondary machine a compact excavator can go years with only minor wear-part replacement, means that you get good value for your money over a long period of time.

Easy on the diesel
Fuel use on Bobcat’s E35 averages 1.2 gallons per hour, a 20-percent increase in efficiency over the E331 it replaces. Over the five years we use in our calculations, that translates into a savings of $1,200, and that’s figuring diesel at $2.50 a gallon. The increased fuel efficiency is achieved with a slightly smaller engine (33.3 horsepower vs. 40 horsepower), new hydraulics and a better match of engine output to hydraulic demand so that you achieve the same amount of work with less fuel burned.

Hydraulic system technology has come a long way in the last two to three years, Connor says, and what used to be available only in bigger excavators has migrated down to the compact lines. Seeing smaller horsepower numbers on the spec sheets causes some contractors concern, he says, “so the only way you can convince them is to let them run it for an hour or so.”

Work tool wear
Buckets and blades vary considerably in their lifespans. A standard 24-inch bucket on this size machine typically lasts 500 to 700 hours. But Connor says in abrasive or rocky conditions he’s seen them wear out in as little as 300 hours. We chose a conservative number, 500 hours, and a bucket replacement cost of $675. Be sure to factor in your own experience and soil conditions when totaling up your cost projections.

Dozer blades are harder to figure. It depends on whether you backfill with the blade or use a second machine. And some operators backfill with the side of the bucket, which puts more wear on the boom and arm linkages. Additionally, the E35 sports an angled blade, and these tend to wear faster than fixed blades. Bobcat designed the angled blade with an easily replaceable bolt-on (rather than welded) cutting edge in anticipation of more frequent replacement. But given the scope of the variables, we didn’t include calculations for replacing the cutting edge, and assume that the blade will last to the 2,000 hour mark. You will need to include this cost if your applications call for it.

Make it last
With compact excavators capable of long lifecycles and low operating costs, strive to take good care of these machines to maximize your dollars. “The best thing you can do is train your operator,” Connor says. “Even if it’s only 10 or 20 minutes.” Make sure they know where the grease zerks are located and make sure they use the right attachments. Use a hammer, for example, to break up a sidewalk or slab, rather than the bucket.

Also watch out for hydraulic fluid contamination from attachments, especially rental attachments. If the fluid in the attachment is dirty or the wrong spec it can contaminate the host machine’s entire system. And keep your couplers and hoses clean anytime you’re changing attachments.