Hi all,

I'm looking to improve mpg. Would I also have to restrict the air intake? Would this make for a more fuel efficient engine?

James and Harry are right.

Efficiency is what creates MPG. If you lean an engine out (eventually) you will burn a piston. Engines can run lean for a period of time (under very specfic conditions), but eventually heat will melt the pistons and/or ruin the exhaust valves. If you remove fuel, you need to remove air to keep the mixture right. Unfortunately, by restricting air intake, you are creating a pumping loss...the engine now has to work harder to force the air in it needs to operate...so you've REDUCED efficiency. Higher compression would make running lean worse, since compression generates heat, and more compression with less fuel will unquestionably lead to detonation and destroyed pistons.

Reducing engine displacement, vehicle weight and drag is how you create efficiency. Note that all the 40+ MPG cars use small engines, and are in the 2000lb range.

By restricting the air intake will just cause more gas to be used and won't change the compression at all.. You might get by the next size smaller jets but if you go to small you will hurt your engine.

I hope you are joking, as your questions do not make sense, and furthermore display an abysmal ignorance of the basic principles of the way any engine works.

no, youll burn a piston

Hi all,

I'm looking to improve mpg. Would I also have to restrict the air intake? Would this make for a more fuel efficient engine?