tcam93

Can anyone give me their experiences with the K&N drop in air filter. I put one in my 2010 JK and my gas mileage went down a little... I could 22-23 mpg tops on the highway but with the K&N I'm lucky to hit 19.5. Also, when I set the cruise with the K&N, the tach dances all over the place. About the only benefit I've seen is that I accelerate better (at the cost of less mileage) but it just seems that the engine can't deal with the amount of air its getting...

No other mods at all.

I'm thinking of just putting the original air filter back in..

rubi08unlimited

I wouln't give up just yet. I've always found K&N or other like oiled filters to get better with time. almost like they perform better with a little dirt stuck to them. I've heard it explained why this is the case but I'm sure someone else could better explain it.

mainejeeper

Did you make any other changes? I haven't had any of those draw backs with my k7n drop in filter. It's the only mod I've made to the engine. My mileage may have went up a bit, but certainly didn't go down any. I bought it for it's long term savings.

TJ2JK

I just put a K&N in mine two weeks. Haven't noticed much difference yet, and haven't checked my gas mileage. Normally with more air flow, the air/fuel mixture is now different and it's not uncommon for the computer to take up to 20 starts/driving sessions of over 10 miles to "re-learn" the change and compensate accordingly. Your idle and low-end RPM should smooth out after you've run it a while longer.
I'll have to check my mileage, but I haven't driven mine but twice since the new filter.....damn front axle seal started leaking so I've parked it for a bit.....my task for Saturday to replace.

Hope this helps.

renpia

Could it be that the loss of mileage is due to more pedal on the floor since the acceleration is better? Maybe your just burning more fuel because you're having more fun?

kingteddybear

I've had my K&N drop in installed for ~9K mi now. I have not had any of the problems you mentioned but when I installed mine I went ahead and reset the Canbus computers by pulling the neg. battery terminal for 10 minutes. RPM's rock solid steady on cruise control. I did not see any increase or decrease in mpg or throttle response due to the drop in. When I added the MBRP cat back exhaust I did pick up +0.4 mpg and a little better throttle response for passing. The increase in mpg was just about enough to compensate for the drop in mpg due to running the AC during the summer. Just my two centavos

SonomaScott

The KnN in my jeep has been there of 18000 miles. I have had over 200k on other vehicles. May want to check to make sure the cover sealed well.

tcam93

I made no other changes. Gas mileage hasn't gotten better at all. I've been about 1500 miles with the K&N (2 months) and not better at all. Tach still dances around...

tcam93

That's what I thought too, but I test by setting the cruise and making interstate runs... now, I'm relying on the electronic mpg deal in the dash.. but, when I calculate after putting gas in... its almost dead on... With the stock filter I would hit 21, 22, 23 on the interstate with the cruise on.. .. but with the K&N, the tach bounces around like crazy and I'm lucky to get to 18 ... best I've seen is 19.5.

tcam93

I wonder if pulling the negative battery terminal might allow the computer to recalibrate based on the better air? I like that I have more get up and go.. it's noticeable... but, I can't stand to loose the milegage .. What exactly does the Canbus computer do, and do you think it would help???