hello again. I recently decided to try out a K&N CAI. I installed it the other night on my 2003 sport and it took only about a half hour. very simple install. anyhow, I know that many say that they don't do a darn thing while others like myself had had some surprising success. Here's how it has panned out so far, only having it in my jeep for a few days. I drive about 80% of the time on highway commuting to and from work...about 72 miles round trip everyday.

prior to the install I was experiencing about 18-19 MPG highway...not that great, not bad but I drive about 70 the whole way...turnpike sees about 72 MPH. I've repeated the MPG test (I dont have any readouts other than watching the fill guage) for almost 9 months now so I know what the jeep is getting. Basically, I was getting about 90-91 miles per quarter tank of gas. I was also idling at about 700-750 RPMs, running at about 2500 RPMs at 70 MPH.

After the install, and keeping the same driving style/speed I have gained considerable mileage per gallon. My first quarter tank of gas, I got 120 miles!!!! Unbelievable!! That's nearly a 35% increase in fuel economy! also, my idling has gone down to 500 RPMs and its running at 2250-2300 RPMs at 70 MPH....thats not bad at all...definitely running leaner.

I have to believe this CAI is making a vast improvement, but will continue my testing in the months and fillups ahead. I really don't notice and major "sound" improvements that many talk about, specifically the nice deep growl that people say, but the engine was already sounding good prior to the install. The car seems more responsive and there is definitely no more lag in punching up to highway speeds...every now and again prior to the install, it would pause before acceleration...not anymore.

All in all, I'm happy so far, and am completely amazed at the fuel efficiency I have gained. i was stunned as I said...I hpe it continues and is not some fluke. either way, I think it improved things across the board, and only time will tell. I am not disappointed since I've read many posts to the contrary...seems like a good product.

later,
Dave

I to noticed a big change when I installed my AFE CAI,I no longer run the oiled air filter and have switched to the AEM dryflow synthetic filter.I'd hate to see what my mpg's would be without it one,only can average maybe 14-16mpg's now,stupid heavy armor !

I love that KJ you have there...I think I could overlook the decreased mileage in exchange for the awesome armor!!! Question, I'm interested in the dryflow filters. how do I determine the size I have now in the K&N. (would like to avoid the whole oiling ordeal when it gets dirty) Is the size the length? the width? the diameter of the hole that mounts over the intake tube? or a combination?

Well I just went to a parts store that carried the AEM dryflow filters and kept trying(or attempting to try on) filters untill I found one that fit.You can go to AEM's web sight and they have a list of the demensions for all there filters,just measure your filter(width,lenght,and opening diameter) and find the part# for the filter that at least will fit on the K&N tube.My AEM filter is about 2" shorter then the AFE one,same diameter though,works awesome and is a breaze to clean.

A little update. While I didn't have the huge fuel increase across the next two 1/4 tanks of gas (I fully knew that was going to be the case and it would level off)...I am still way ahead of the game. I am roughly about 4-5 MPG more than without the CAI and being all highway driving, I see those bigger numbers right off the bat. I will repost when I run the tank almost dry, and then follow up with after another full tank. More importantly, I am seeing the solid power increase across the board still too. Absolutely no hesitation at any speed. Very responsive and the RPM's are even a little bit lower than the first few days as well...from idling to top highways speeds, now about 250 RPMs lower consistently. I'm happy thus far. I was looking at the dryflow filters yesterday at my local shop, but they didn't have my size...I may just order one of those online down the road, after I start checking the intake line to see how clean/dirty it is...I'll use up the K&N as much as possible...why waste money yet.


Edited to add: First full tank of gas run gone through. Increase in mileage: 55 extra miles on a tank. Leveled off at about 2.98 more miles per gallon of gas. Just filled up and will see if that holds for the second tank.


Edit to add: Filled up again, got 198 miles in the first half tank of gas....not too shabby, still chuggin away.