Bolt-ons = less restrictive, Better MPG???

frost

There is some potential gain (1-2 mpg in my experience).
If we were to say there was NO gain to be had by an engine breathing better, we would also be saying that it doesnt matter how filthy an air filter gets, it won't affect your gas mileage.

kannibul

RE: dirty air filter / MPG

I think it's more of a case of the ECU having to compensate with using more fuel for less air (at speed), to prevent a lean (and potential detonation) condition.



The only way to get more power, is to increase the amount of air going through the engine. The only way to make that air to burn and produce power, is to add fuel. Fuel-to-air, is a fixed ratio (relatively speaking, theres only a slight variance...). Therefore, no matter how much air you can get through the engine, with fuel-air ratio and total efficency of the engine's ability to convert fuel-air into real power...your MPG will NOT increase.