Have any of you experienced LOWER gas mileage after installing their
aftermarket intakes?

I've got a Frankencar with a JWT intake (K&N Filter) and though I
havent run any specific tests, I feel as if my gas mileage has decreased.

I've tried cleaning the filter and re-oiling it and I've even purchased a brand new filter but it appears to feel the same way.


When I put in the stock filter my gas mileage is much improved.

I've had the Frankencar/JWT set up for quite some time now...

Anybody else experience anything like this?

 

This just means your computer is doing it's job and has adjusted to having more air flow. With more air flow going into the engine you need more fuel otherwise you create a lean condtion. I am suprised you noticed a change though it should only be very slight.

 

Ease off the pedal. I bet you've been flooring it to hear the intake.

 

I stopped doing that a while ago.


The change is more than slight.......

I guess I'm the only one that noticed a difference?

 

I actually noticed a slight improvement. I have the Apexi filter and have had it on for about 8 months. I check my mileage on almost every tank. Improved about 1 - 1 1/2 mpg.