“We don’t know why more fleets, big and small, are not buying 6x2s. Our investigation shows that the benefits are clear.” 

General Manager at a tractor OEM

The chassis system is defined as all of the parts in the tractor that carry the cab, hood, and powertrain. This includes frame rails, cross-members, axles, fuel tanks, battery boxes, etc. Although generally not an area for significant fuel efficiency options, new technologies are emerging. One example is the expected increased adoption of 6x2 axles.