K & N Air Filter
 

I've been reading a lot about the K & N replacement air filter for my SL. Boy, opinions are all over the place some pro, some con. What's the opinion of this knowledgable forum. I wouldn't want to put something in my SL that in the long run will harm my engine.

Bruce

No way...don't go there! See here for starters.

There's no way I would risk my Air Mass sensor for a couple of BHP - if you’re lucky. Anyway, as JJ so rightly pointed out - even if you do obtain the massive 10BHP do you really think you'll notice considering we have around 320??

Ah, sorry I see you have a 300SL I thought yours was a 500 for some reason. Anyhow the percentage performace gained is still so minimal it still begs the question; is it really worth it. So had you say that you're thinking of adding a super charger (kompressor) that would be different!! :)

Lea

I put one in when we bought the car...actually two of them :)...and no problems and no improvements noticed so far.

nice to see some honesty... ;)

The Porche Club performed testing and found no performance increase on K&N filters. I have run them in almost every vehicle I owned since 1973 (dirt bike). When new, they allow larger particles tha the paper filter then get smaller as they collect dirt. The dirt soaks up the oil and becomes part of the filter. This is at the micron level. I like the K&N's but they mostly just make the intake a little louder. I doubt it could hurt the air flow sensor. It is a hot wire thype, isn't it? How could it possibly hurt it by allowing particles 2 microns larger than the paper ones? Urban legend?

I like the fact that you cna clean them and they last forever.

I have used the KN for quite some time in other makes and have determined the advertised performance increase is mostly probably due to making a comparison between a clean KN and a dirty paper element. Potentially fouling sensors aside, the KN advantage actually lies in its life span due to your ability to clean and re-oil it.

That said, I noticed that one of the KNs sitting on the garage shelf was the same part number listed as a replacement for my 107 paper element. I tried it and immediately noticed it is about 1/4" shorter than the Mann paper elements. This difference results in it not fitting tight inside the filter housing on my car without the addition of a foam strip around the base of the housing for it to seal against. My conclusion: not worth the effort and potential for downstream troubles unless you really need to change filters a lot. Use your car as a summer toy, like I do, and the Mann elements will last for years before you need to replace them.

[QUOTE=230/8;2536538I tried it and immediately noticed it is about 1/4" shorter than the Mann paper elements. This difference results in it not fitting tight inside the filter housing on my car without the addition of a foam strip around the base of the housing for it to seal against.[/QUOTE]

Hmmm...no wonder it's so efficient with breathing...:)

Or, reminds me of high school, where kids used to flip their air cleaners for "more power", sound, and, of course, "automatic overbores"!!!!

FWIW:

I used to send my used oil from my 2000 Ford F250 Diesel to Blackstone Labs for analysis.

One time, the sample came up with high silicon levels. The lab tech asked if I had switched to a K&N type filter, which I had.

After doing some more research, the consensus is that the K&N type filters do not filter as well as the paper and the lab anaylsis confirmed that.

I don't go by speculation anymore on this issue.

FYI
 

K&N filter topic links thread
http://www.peachparts.com/shopforum/diy-links-parts-category/173036-k-n-filter-topic-links-thread.html#post1354738