Another thing to ponder is hearing people say--- "ever since I increased the power of my engine I now get better mileage".
It seems a contradiction that using more fuel will give you better mileage.
It isn't a contradiction... it's simply more efficient
to overcome the transmission, rear end, tires during acceleration with a higher Torqued/HP engine.
You've also changed the "Sweet Spot" of the engine
thus making it more efficient within the range that you normally run.

https://www.barthmobile.com/eve...=601104333#601104333

What should be the "optimum" sweet spot?

quote:

Originally posted by Doug Smiley:
It seems a contradiction that using more fuel will give you better mileage.

It is a contradiction, it is impossible to use more fuel and get better mileage. Using the same amount of gas more efficiently, to produce more power from the same gas, will increase the mileage.

Higher compressions are the easiest way to increase efficiency, this is why diesels and turbo/supercharging works so well. Improvements in engine breathing and uniform fuel delivery also help.

Ideally, the engine rpm should be at or near the torque peak when at cruising speed, usually achieved by selecting proper driveline gear ratios.

Good example: When I replaced my 454 engine with a higher compression engine, my mileage went from 6-6.3 to over 7. Using less fuel, about 15% better efficiency!