Installing engine air filter... which way is up?

[TrevorInsight]

Not a big fan with the K & N Filter for this vehicle. I installed one in mine and used it for about 30 miles or less; I was averaging around 8-9 MPG less over a paper filter.

[Willie Williford]

Air cleaners will only effect your mileage IF it is restricted. There are both pros and cons about using a K/N filter. It all boils down to owner preference.

Willie

[TrevorInsight]

Can you explain the differnce in fuel economy I was experiencing?

[Willie Williford]

Nope, I wasn't there to witness how you drove. Not to be sarcastic but there are to many variables to say that the filter was the cause of the loss in mileage. Once changes are made, the ECU has to adjust to those changes, so it will take several "drive cycles" to make that happen. I don't think it can be done in 30 miles.........My opinion.
Maybe at the next AZ meet, we can devote some time to different scenerios for testing.
HTH
Willie