zoomie

A couple people have had bad experiences with the K&N's in terms of worsening gas mileage or messing up their MAF's. I have a few questions.

1. What ever happened to the MAF's? replaced it? fixed it? Cost of damage?
2. Has people's gas mileage changed after installing the K&N air filter?

If you have comments about K&N vs. Green or other filters, please post them in one of the zillion other threads about that. Please reserve this thread for K&N's effects on gas mileage and possible MAF damage. Thanks much!

HLG600

These MAF issues arise from using too much oil when "recharging" the filter. To avoid any issues whatsoever with the MAF, just throw out the K&N's after the recommended mileage and replace them with a fresh pair. The additional cost of new filters is a lot less than having your MAF replaced.

I've had K&N's in my car for almost 15,000 miles now. Not a single issue. However, I won't even bother trying to re-oil it after 50,000 miles of use. Like I said, just easier to purchase a new set then.

zoomie

Thanks for the response. Buying a new K&N air filter everytime does lose it's purpose of being reusable. Gets expensive after awhile. Can you share some words concerning gas mileage differences with the new K&N please?

JRAMGV8

I put a KN Filter on my previous C280 and never had any problems. You notice a little bit more on the throttle and more revs but other than that it was great. I have replace the Air Filter twice and I had the car for almost 4yrs.

As I have the new E350 I plan to put one in it or an Air Hog Filter.

zoomie

...and as for gas mileage differences between stock and K&N?

HLG600

Honestly, I barely notice any fuel economy difference with it. The most effective way to keep fuel economy up is correct tire pressure, quality gasoline, and highway driving.

jturkel

yah, like previously stated, there should be almost no difference between stock and K&N filters. It allows a little more air to come in making you have slightly better throttle response and maybe MAYBE (i emphasize the maybe) an increase in 1 - 2 hp, especially on an N/A car.

If you want better gas mileage, HLG600 gave some good suggestions. Also, slower acceleration will result in better gas mileage.

jturkel

i would recommend to just replace them with new ones as well. its not worth messing up the MAF sensor. And you mention that buying a new K&N filter every time gets expensive....while you do replace them, you dont replace them yearly, at least i dont. i think the both of mine cost a combined $90. And what is another $90 every other yr or every 3 yrs when you drive a $25K,$30K, $35K+ benz?

zoomie

true....changing K&N filters i guess isn't so bad. I'm thinking more of a percentage difference in cost rather than the actual dollar amount. How often should the K&N filter be replaced then?....50k miles?

jturkel

honestly, i have not cleaned mine yet or even replaced them. The K&N website says they dont need to be cleaned for at least 100K miles. From the searching i have done, most people agree with that. However, the Green Filters (if you were to get those instead) get dirtier faster and actually need to be cleaned every 30K miles.

I've had mine on since 26K and I now have 62K. I have had no problems with my filters at all.

IngenereAMG

I have been using K&Ns on all my cars and we recommend them to the cars we tune. I have never experienced any problems at all. They help our tuned cars breathe better.

As far as gas milage goes......Its hard to say, as I am a serious lead foot!

HLG600

We share the same "problem."

Tyler Durden

So far the K&N drop-in is the only mod on my S55. I'd agree with the other posts here that the problems arise from excessive re-oiling; the way they come out of the box is fine and they're oiled perfectly. I'm gonna keep any eye on them (since I'm gonna have the car forever!) and when they're ready to be serviced, I'll swap them out for a new set. Price wise I guess it all works out...

CLK Masters

i've had great success with just K&N filters.

I ran a 14.19 @99.2 mph stock, and 13.95 @100.56 with the addition of K&N's. this was done in the same night on the same track in the same lane with no more than 3-4 degrees of tempature change in the weather and no change in humidity. same tires and same launch sequence/technique.

I could never break 100 mph in the 1/4, since the K&N's always in the 100's.

now i've got exhaust & no secondary cats.

Last time @ the track i ran a 13.7 @ 103.5

IngenereAMG

Perhaps we should start a support group!

zoomie

Have you guys found that after you let go of the throttle with the K&N installed that the car coasts less? An other words you have to keep the gas pedal depressed for longer?

1FSTAMG

That couldn't have anything to do with the K&N.

calimax

I gained 3 MPG with a new set of K&N filters in my C320. I had tested the MPG every time I was on the HWY @ 60-65-75-80 MPH and watched the screen every day for two weeks. I started with 23MPG at 65MPH. The K&M brought it up to 26-27MPH. Keep in mind that this test was with OLD stock filters.
Personally I get a little scared when I see the new filters out of the box. How the hell could a person over oil it more than K&N already did??? Some of the boxes I've seen are SOAKED with the oil and the plastic bag has oil everywhere.

zoomie

It does.....b/c it changes how much air goes in. It happened on my rav4. Does your answer suggest that you have NOT experienced lag after letting go of the throttle with the K&N installed?? any help would be great.

IngenereAMG

I have never experienced anything like that, and our clients haven't said anything to us.

1FSTAMG

No, when the throttle closes, there is only a very small amount of air going into the motor. At that low amount of flow, the K&N isn't flowing much more than stock filters.

If your theory were correct, then what would happen if you removed the filters completely? Would it "coast" even easier? I don't think so.

i've been known to be wrong though.

zoomie

Thanks for responding to my question. I've been waiting to hear for some time now.

I'm not saying that the K&N filter would definitely do that. I just have no clue and figure there's tons of people with the filter installed that can chime in but i haven't heard much. I'm only wondering b/c i experienced the lagging of the coast with the rav4 and it was really annoying. I had liked that i can let go of the gas and have the car coast for awhile. the K&N ruined that but did respond a bit faster and sounded pretty cool.

$tallion

CRC Cleaner for the MAF thats what the shops use spray it off every few months for clear results

wawy

Good Popular Mechanics article for cleaning your maf sensor here:
http://www.popularmechanics.com/auto...o/3297276.html

ewill40

Its funny that I saw this thread today, as I was looking for the same answers as the op a few weeks ago. I just recently purchased a 2002 c32 w/60000 about a month ago.After not finding a definitive answer I just decided to give the k&N's a try two days ago. Before, on my drive to work (all fwy 60-70 mph) I would get 19-20mpg as charted on my screen. Now after the k&n's I have been getting a solid 23, and if I punch it (just for a little bit, there is still morning traffic) it will only go down to 22 or 21, where before this was the max. So far it seems to have helped m mpg.