This engine in the car theory is a very good example, You have torque and resistance. At first it seemed wierd to me but after I thought about it, it is almost the same. Now What you are saying is that the same engine is in both cars. Yes the Suburban will be working harder. If it wasnt then the two vehicles would get the same gas mileage (lets forget about gearingcause we are pretending it is the same in both vehicles) but as it is at wide open throttle the engine requires more fuel to move the same distance than it would in a lighter car. Oh, and Red. I know about the gear trains and all that crap. And you are right, it may only take that much to get the surface to 45 degrees, but it will take quite a bit more to keep it there at that speed. I didnt metion that and I should have.