Thread: Hybrid Discovery Unlikely - but it's coming

one issue I see, to my layperson view, with an electric motor on each wheel is the loss of torque as traction is lost on various wheels assuming 4 individual motors would be smaller(torque and power) than a single central motor through gear box and diffs.

They would be great when all four wheels have grip but what happens when only one wheel has traction? You only have one small electric motor trying to move the car, the torque of the other three motors can't be transferred to the wheel that has grip.

Sound logic or not....?

Originally Posted by Silenceisgolden

Excellent question, Meken. 500,000 Diesel-electric locomotives can't be wrong! If the process was not fuel efficient, I am sure the train makers would not have gone that way.

With modern electronics, just imagine the algorithms that could be used in off-road vehicles! It would be the ultimate in efficient traction control. Much better to apply power to the wheel with best traction rather than applying a brake to the wheel with least traction.

The popularity of diesel-electric transmission on railways is not because of its efficiency, although it is undoubtedly as efficient as any alternatives, but because it solves the problem of producing maximum torque at zero rpm (inherent in some types of electric motor), needed for starting, and at the same time solves the problem of driving six axles in two bogies without gears, shafts, or inefficient hydraulics.

I suspect that electric transmission could be no more expensive than current systems, especially for a four wheel drive, but I can see some potential problems - motors, cables and the alternator would use a lot of expensive copper and be quite heavy unless quite high voltages were used. That in turn leads to potential problems with safety and operation in a wet and dirty environment. I'm not saying this could not be solves, just that it would be expensive to solve. RFI would be a potential problem, and could cost quite a bit to solve.

John