Diesel vs gas......................

rhagfo wrote:
It isn't HP that moves the load it is torque! HP gives you speed, I currently have 610 FT lbs. of torque produces by my 01 Cummins, adding RV 274 injectors to the mix too see if I can do better on winter fuel.

This has probably been explained many times in this thread but I'll give it another go:

Torque is nothing more than a force which by itself moves nothing. I can apply 100 ft-lbs to my lug nuts yet there's no load moving. Power is the measure of force applied at a rate. Once that torque is applied over time you move the load. That is the very definition of HP. So yes, torque is the force involved but HP is the measure of power used when applying that force over time.

The torque at the crankshaft isn't what moves your truck anyway. It's the torque/HP at the rear wheels. When you send a high torque engine through higher gearing the wheel torque will be the same as a low torque engine with lower gearing (running at higher RPM), provided both are producing the required HP.

Since you mentioned your truck, here's a comparison: My 8.1L produces 455 ft-lbs @ 3200 rpm. A stock 2001 Cummins produces 505 ft-lbs @ 1600 rpm. If the 8.1L is in a 2:1 gear it will output 910 ft-lbs @ 1600 rpm at the driveline. The Cummins in 1:1 gearing still produces 505 ft-lbs @ 1600 rpm at the driveline. The reason is simple: The 8.1L has more HP at its torque peak than the diesel. It's cranking that lower torque around and around at a much higher rate.

rhagfo wrote:
JUST and FYI a gallon of Diesel has more power than a Gallon of Gass!

Yes, there is more energy available in diesel though the larger reason they are more efficient is because they are not throttled.