K & N Air Filter

[Mighty Quinn]

Thought you guys might want to check this out:

http://www.bobistheoilguy.com/airfilter/airtest1.htm

It gives me second thoughts about trying a K&N filter.

Cheers,
TMQ

[Lotus99]

I have the 3.2l engine. Sounds like my mileage is consistent with yours.

Makes sense, as both engines have pretty much identical EPA mileage ratings from what I recall when I was researching them.

[Lotus99]

Thought you guys might want to check this out:

http://www.bobistheoilguy.com/airfilter/airtest1.htm

It gives me second thoughts about trying a K&N filter.

Cheers,
TMQ

I didn't read the whole main page, or the links there, but a quick skim of the main page said:

"For the record, the K&N was the best flowing filter."

What was it you read that caused you concern?

[BillAileo]

Perhaps it was the paragraph reading:

"Well there is a clear pattern on filtration ability compared to both flow and the type of filtration media used. The "high performance" cotton gauze and foam filters do not filter as well as some have claimed. I actually received an e-mail from K&N stating their filters filter within 99% of the OEM filters. This may be true, and 1% may not sound like much. I contend that 1% over many miles, may be important. Really, it is up to each individual to decide. The poorer flowing filters, remove more particles, and the better flowing filters remove less particles. If you think about it, that conclusion passes any and all common sense tests, so it is not surprising. There are many that will be shocked by the results, that should not be though. I've used high performance filters in the past, and I might again in the future. At the same time, I know that the stock OEM type filters perform very well in filtration and don't inhibit flow nearly as much as some think."

[Mighty Quinn]

I didn't read the whole main page, or the links there, but a quick skim of the main page said:

"For the record, the K&N was the best flowing filter."

What was it you read that caused you concern?

It is worth while to look at the detailed pressure drop results. While the K&N filter had the lowest pressure drop (least restriction to air flow), the difference was quite small.

The message I got from this testing was that you do not get something for nothing. The K&N filter has slightly better flow, but this comes at a price: less particulate capture.

So right now I am leaning towards not buying the K&N filter. However, I have to admit that I am a very curious person. If I continue to keep good track of my mileage, and my driving habits stay relatively constant, then I might try the K&N filter just to see if I get a statistically significant change in mileage.

Cheers,
TMQ

[mbsl98]

I tried a K&N filter on my MB 380SL a few years ago. This is a hobby car and only goes out in good conditions, so little heavy filtering generally (compared to bad weather, snow/rain with sand and salt, etc). I would up pulling it off after i noticed that i could feel a very fine grit on the fuel injection throttle body intakes, with my finger, after about 3k miles. Not scientific at all, but it bothered me that the K&N seemed to be letting in enough added particulates to actually feel. Obviously, this is an old-tech V8 engine, and the newer systems may be much better, but it turned me off, particularly since I never noticed any particular improvement in performance.

[OKCXC70]

I have a 3.2L 08, non-turbo. I get 19-20 city and 23-25 highway. I have a lead foot, too. I usually use 91 octane, but if the price goes up I'll use 89. Here in OK we have 87, 89 and 91. You can find 93 octane occasionally in some places. I do not use ethanol blended gas. I have 8700 miles on the car now in 7 months.

[Hiro's XC]

Oiled filters are a BAD idea. They let lots of particulate through and will DESTROY turbos by slowly sand blasting them to death.

The other issue is they destroy very expensive mass air flow sensors. Stick with the paper element.

Jeeps are NOT modern engines. There is NO comparison.

I own a shop FWIW. Not just speculation.

[Lotus99]

Oiled filters are a BAD idea. They let lots of particulate through and will DESTROY turbos by slowly sand blasting them to death.

The other issue is they destroy very expensive mass air flow sensors. Stick with the paper element.

I can't comment technically, but on your point about ruining MAF sensors, I do recall on the Audi 1.8T forums, lots of people had their MAF's go bad, and one of the big speculations as to the cause was the K&N filter for the reason you point out above...