[JRMichler]

777,
I appreciate your detailed reply. I was not aware of the Remy motors. They are impressive. Much of my own motor experience was helping develop a liquid cooled permanent magnet servomotor. That motor was rated for 225 ft-lbs continuous torque and a base speed in the 1000 to 1500 RPM range depending on the exact stator winding. The motor itself was less than 10 inches diameter by about 16 inches long.

The justification for a hybrid OTR truck makes a lot more sense when you mentioned running at 10% load. That's way below the BEP, even for a diesel. Plus the fuel wasted idling and during low speed maneuvering.

Some number crunching indicates that you really went after friction and rolling resistance. Some of us would like to know what you did, and especially how applicable it would be to our vehicles. Or should I just reread Dice1's thread on thetruckersreport.com?

All of which begs the question: If the steady state cruise power is so low, does such a truck really need a 13 to 15 liter low RPM engine? If the steady state power is down around 60 hp or less, could one of the engines such as the new Ford diesel in their medium duty trucks be used?

In that case, the weight savings from a lighter engine, no transmission, and no APU should come close to covering the weight of generator, electric motor, drive, and battery pack. The battery pack would need to be on the order of 100 Kwh in order to handle the necessary power without catching fire or blowing up.

I'll make a WAG and guess the BEP of a lighter engine to be around 2000 RPM. Which would imply a rear end ratio to get 2000 RPM at 55 MPH. And a high torque version of the HVH motor with the stator wound to get the base speed somewhere below that.

Methinks that you have a goal of 20 MPG with your series hybrid.

I'm not convinced that any of this is new to the engineering departments of the big manufacturers. Being an engineer myself, I would bet that the engineers are tearing their hair out with frustration that management won't listen to them. And that those same engineers have done work way beyond anything said in this thread.