What is the benefit of an aftermarket throttle body besides the gain in horsepower?

What happens to the gas mileage?

 

IMHO you will not get a power gain on a factory-stock engine.
But if I'm mistaken, and there are minimal gains to be made, then they would only be at the top of the RPM scale at WOT.

Even guys with blowers tend to keep the stock t-body, if that means anything.

Your mpg will be the same until you start flowing more air, wich will again be at the top of the RPM range. At anything other than WOT, there will be no effect to either MPG or power...because the throttle will be limiting airflow, so you won't be taking advantage of the larger t-body's greater flow. Assuming your engine can ingest the extra flow, which I don't think it can.

Just my two cents

 

You won't see a big hp increase as such, you will notice a crisper throttle response, and easier reving motor in most cases. Your mpg shouldn't be effected, unless you hammer it alot.

 

I put a 75 mm -body with k@n filter. I had little gains. It didnt do much for mpg also.97 F-150 4.6 L.

 

They also make the air travel further, to get to the engine, so positive impact is negligible . . . modification at best.