"Thats not true, in the sense that you're talking about, it has to work EXACTLY as much as the iForce. What you're talking about is the fact that it is bigger, so it can perform MORE work at its max. The difference in mileage is not a factor of the engine having to work less, a bigger engine will never let you drive and use less fuel than a smaller engine. Diesels and some niche forced induction gasoline engines are the only things capable of doing something nuts like that.
The difference in mileage can only be accomplished by differences in the vehicle themselves (aerodynamics, gearing, engine tuning), or by bad math, or by using different top-off methods when refueling to calculate milage."
What I'm saying is that I usually get 19mpg on Highway and when I tow I get like 10 on highway, he usually gets like 15 on highway and gets about 12 when towing so there's a big loss between mpg of the vehicles he only loses 3 with the same load while I lose about 9, so the bigger engine tows the same load a little easier, I agree about the differences in aerodynamics, and etc....