but in the end to make more power you use more fuel every time the engine rotates. the way that the mileage is kept reasonable is by the

higher gear ratio

in the axle that allows the engine to turn less rpm at a given speed. the same holds true if a normally asperated engine is bigger and more powerful, you can achieve the same mpg with the same car by using higher gear in the rear end or an overdrive in the tranny.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.