The World’s first hybrid bulldozer  

Bob Morris at Polizeros has a post on "World’s first hybrid bulldozer" from Caterpillar.

The D7E represents a mid-range dozer between Caterpillar’s popular D6 and D8 models, and commands a price premium of 20%, or $100,000, over a standard D7R. But that 20% can be recouped in as little as two years thanks to fuel savings of 10-30%

It has instant torque and requires less maintenance than standard models.