I swapped my F-150's stock air filter for a high-flow unit expecting better mpg, but my fuel economy actually dropped by about 2 mpg on my regular highway commute.

The mechanic said the engine computer might have been compensating for the richer air mix by adding more fuel, so has anyone else run into this and found a tune that actually helps?

3 comments

3 Comments

dylanwilliams27d ago

That whole "computer adding more fuel" thing sounds like a guess... it's probably not that big of a deal. Two miles per gallon could just be from you driving a little differently or the weather changing. Maybe just swap the old filter back in and see if the number goes back to normal.

rivera.nathan27d ago

Hold on, you think a two mpg drop is just the weather? That's a huge swing for a daily driver. The computer absolutely can overcorrect for a new part it doesn't expect. Swapping the old filter back is the only real way to know for sure.

andrew_kelly27d ago

Tried the same thing on my Silverado. Got a custom tune from a local shop and it fixed the fuel trim issue. Gained back the lost mpg and then some.