E-quipment highlight: Caterpillar D6 XE electric drive hybrid dozer

The bright yellow D6 XE dozer might look like your everyday medium-class dozer, but underneath that vibrant bodywork it’s hiding a highly efficient electric drive system that Cat says makes it the most advanced hybrid dozer on the market.

Operating more like an extended range EV (EREV) than a conventional hybrid, the D6 XE runs a Cat C9.3B diesel engine that operates as an electrical generator, feeding power to electric motors that drives the dozer’s tracks directly. The result is instant torque, smooth, high-precision controls, and 35% better fuel efficiency (and, as a consequence, significantly lower emissions) compared to the diesel-only D6T.

35% is big in a segment where equipment can and do regularly burn 25 gallons of red dye diesel per day, and that number only gets bigger when you factor in the oil and maintenance costs saved from ditching the conventional transmission altogether. Combined with the reduced number of moving parts and reduced metal fatigue from vibration-free running, and Cat estimates its D6 XE electric drive operators are saving over $1/hour of operation in rebuild savings, alone — that’s a game-changing number!

“(A full rebuild) can be up to roughly 60 percent of new machine price,” says Sam Meeker, marketing professional at Caterpillar, citing the need for a typical rebuild at the 10,000- to 15,000-hour mark. “So you could be getting a half-price dozer for that second life.”

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Turbo encabulator

First introduced in 2018, the newly updated Cat D6 XE features a switched reluctance electric motor and generator instead of the previous, permanent magnet system used in the first-gen Caterpillar electric-drive machines. The newer drivetrain is more power-dense and efficient, and makes for a generator that doesn’t require a massive, maintenance-intensive cooling system.

“We like to run this machine at a lower RPM, not only for fuel efficiency, but then it allows us to lug up into a load,” adds Meeker, hyping up the big hybrid dozer. “So when we pull the load on, instead of the tractor lugging down, it actually increases the RPM and the power output, maintaining that consistent torque … we only make as much power as we’re going to use, and we generate less heat than previous designs.”

In a bid to encourage more operators to give their electric drive models a try, Caterpillar is offering on-demand learning resources through its online platform, catoperatortraining.com. Designed to be accessible any time and from any device, Cat’s is particularly valuable for operators, whether they’re digital natives or just learning how to navigate new technologies. The company is also partnering with global equipment rental fleets like Plantforce in the UK, which (if nothing else) is absolutely phenomenal at taking pictures of heavy equipment.

Electrek’s Take

While there are a lot of people outside the urban construction space who may scoff at environmental concerns, the quest for improved efficiency and cost reduction among commercial fleet managers knows no political ideology. Add in more restrictive noise regulations and the side benefits of improved job site safety and fewer sick days, and electric equipment is a no-brainer.

Simply put: If it’s better or cheaper, fleets will buy it. If it’s better and cheaper, they’ll buy two — and electrically driven heavy equipment assets are proving to be consistently better, in a broader scope of use cases, than diesel alone.

SOURCE: Caterpillar, via Heavy Equipment Guide; featured image by Plantforce.