But if you want top fuel economy-with surprisingly good performance and drivability-in a rig that spends most of its life on open highways and at 80,000 gross weight, Cat has some intriguing ideas.

Truckers and fleets seeking to operate a high-horsepower truck can now order the Caterpillar C15 engine in 625 and 600 horsepower ratings in Kenworth’s W900L long-nose conventional. "Kenworth is ...