I recently (2 weeks ago) installed a K&N replacement filter into my 2K1 SE-AE. Decided to get the better filter and see how the car performs.

The engine has a little more power and responsiveness in the lower revs than before and has a bit more growl which is nice, but there has been one very negative aspect...

Fuel economy has gone through the floor. Even with the old dirty cheapo paper filter I was able to get about 300 miles on a tank of gas. Since the K&N filter has gone in, I have been averaging about 230 - 240 miles per tank.

This is contrary to what I was hoping to achieve with the K&N. I was expecting a slight improvement in fuel consumption with the K&N and would have been very happy with with a slight degradation given the performance improvements. But this is something like 20% worse than before. This sucks in Northern CA where premium fuel cost $1.80 a gallon!!

NOTE: I did not disconnect the battery to reset the computer for the filter, but I have read here that the ECU in the Max will adapt to the new filter, just more slowly.

Any ideas or suggestions? Help?

 

I'm a little surprised you can tell such a difference from a drop-in filter, but maybe your improved performance and responsiveness with a bit more growl means you're getting on the gas a bit quicker and maybe that's contributing to your fuel milage issue.

I'd put my money on your foot before the filter on this one.

Mike

 

Something doesn't sound right here. You should not hear any change in your intake with just a drop in K&N filter. It just aint gonna happen.

Check your installation, make sure your airbox is closed properly and all the connections to it are OK.

The extra growl you hear just aint right, neither is the fact that your gas mileage has gone down so low. Something isn't right. As simple as an air filter change is, I have a feeling somewhere, somehow, something didn't go back together the correct way.

 

most of the time it is just ur mind playing games.....u knew that u put something better and your mind just keeps telling you that you are faster now. But in fact.....I would say it is hard to notice anything below 5hp on butt dyno. U may feel more engine being more responsive.

about the gasoline comsumption....do u go WOT often after replace the panel filter? does your driving style change after the K&N install?? I have a GLE auto and I get 340miles on average per tank, 370 now b/c I am very easy on gas pedal these few months...about 23, 24 mpg.

btw, I am from Fremont.....visit the westcoast forum sometimes...a lot of bay area peopple.