Anybody using K&N air filters? Good experience?

pcohen15 · 01-18-2019, 10:07 PM

I'm interested in knowing how forum members who use K&N air filters like them. (Just the drop-in filters, not the housings.) Notice any difference at all from stock? Have you cleaned and reused them? Did you buy the K&N cleaning kit? Would you recommend?

Thanks!

randrews15 · 01-19-2019, 05:10 AM

I've used them in several cars with no issues. The gain is minimal but you can certainly feels a little pep out of the motor. Having said that, in my M I have the Macht Schnell stage 2 intake and there was a much bigger bump in the feeling and sound out of the motor. I'd stick to the drop in filter, as I don't care for the looks of K&N's performance kits at all.

TomHudson · 01-19-2019, 06:07 AM

I’ve used them in forced induction cars, with excellent results.
This car has the Dinan intake, same type filter.

I like the convenience of cleaning it myself and not having to order and change the paper element.

IamFODI · 01-19-2019, 10:41 AM

Like most OE filters these days, BMW's are good enough that unless you're installing a filter with much more surface area (and sometimes even then), you should expect any filter that flows more to also let in more dirt. Food for thought, especially as the stock filter isn't a major point of restriction. More dirt is a tall price to pay for basically no real gains.

For an oiled filter, there's the additional challenge that the cleaning and re-oiling has to be done perfectly or you'll end up with reduced flow, increased dirt ingress, excess filter oil in your intake, or some combination thereof.

I can see the convenience argument. Personally, I'd rather tack an OE filter onto my FCP Euro parts order every once in a while, send the old one back with my next return to them, and save myself the time and effort of cleaning and re-oiling.

All-in-all, for a custom intake on a high-HP car that doesn't see a lot of miles, I can see going with a K&N. But for an OE-replacement filter on a stock intake in a regularly driven car, I'd stick with OE.

joe6mt · 01-19-2019, 04:12 PM

I have the drop in K&N air filters used for about 2K miles. The gain is very minimal, but you can defi felt the induction noise a tap lounder than OEM filter. I wouldn’t re-oil them, when time to replace them just get a new one. I had the Eventuri intakes, is gain and induction noise is nice and a day diff thou.

pcohen15 · 01-19-2019, 05:35 PM

Thanks for the feedback. At 5-7k a year, I think I'll go the FCP/OEM replacement route.

Richbot · 01-24-2019, 10:59 AM

Quote:

Originally Posted by IamFODI

Like most OE filters these days, BMW's are good enough that unless you're installing a filter with much more surface area (and sometimes even then), you should expect any filter that flows more to also let in more dirt. Food for thought, especially as the stock filter isn't a major point of restriction. More dirt is a tall price to pay for basically no real gains.

For an oiled filter, there's the additional challenge that the cleaning and re-oiling has to be done perfectly or you'll end up with reduced flow, increased dirt ingress, excess filter oil in your intake, or some combination thereof.

I can see the convenience argument. Personally, I'd rather tack an OE filter onto my FCP Euro parts order every once in a while, send the old one back with my next return to them, and save myself the time and effort of cleaning and re-oiling.

All-in-all, for a custom intake on a high-HP car that doesn't see a lot of miles, I can see going with a K&N. But for an OE-replacement filter on a stock intake in a regularly driven car, I'd stick with OE.

The oem filter for early cars has a charcoal element that costs a few hp it’s been covered over and over. Filter is worth a few hp on the dyno . Most aftermarket filters have significantly more pleats

There has been no difference on insolubles in the oil on my car over the 114000 miles I’ve owned it , 80k or so with an aftermarket filter. I have the blackstone receipts. If there’s more dirt getting in it is not causing oil contamination of any significance. More dirt doesn’t mean it’s a meaningful difference.

I have used the AFE, Macht Schnell and K&N. Quality on the K&N seems best of the three

Z K · 01-24-2019, 12:08 PM

I have been using the Active Autowerke Green filter. Besides needing to clean and re-oil it every oil change or so, it has been working good. Oiled filters don't affect anything on the car as the M3 doesn't have a MAF sensor. From bad past experiences, I would not run a oiled filter on any MAF equipped car.

Lots of tar-like black build up from track use though. The cleaner can't clean this stuff off - I have to scrub it with a brush. I don't think this would be any different with any air filter.. it's just track life.

TomHudson · 01-24-2019, 12:41 PM

Quote:

Originally Posted by Z K

I have been using the Active Autowerke Green filter. Besides needing to clean and re-oil it every oil change or so, it has been working good. Oiled filters don't affect anything on the car as the M3 doesn't have a MAF sensor. From bad past experiences, I would not run a oiled filter on any MAF equipped car.

Lots of tar-like black build up from track use though. The cleaner can't clean this stuff off - I have to scrub it with a brush. I don't think this would be any different with any air filter.. it's just track life.

I had a supercharged e36 M3 that never had that issue! Ran it, tracked it, for 14 years!

Either you way over oiled the filter, or you had another issue!

Z K · 01-24-2019, 12:58 PM

Quote:

Originally Posted by TomHudson

I had a supercharged e36 M3 that never had that issue! Ran it, tracked it, for 14 years!

Either you way over oiled the filter, or you had another issue!

The intake tract is very different on the e92 m3. The air from the front of the car flows directly onto the bottom of the filter from the front bumper. I think it's vaporized tire and exhaust blow by build up from other cars with no catalytic converters. The air filter side that is not facing the airflow is clean. Inside of the filter is also clean so the filter is doing its job.

Richbot · 01-24-2019, 01:45 PM

lol yeah the E36M didn't have a square foot of intake in the front bumper a foot off the ground aiming everything down near road level, like dust kicked up from other cars, pushing it through a duct aimed directly at the bottom of the air filter. It draws air from behind the front splash guard (aftermarket) and or the engine bay, uses a panel filter, etc. not the same at all and this is the only car I've had that fouls filters like this it's amazing how gross they get on the bottom.

but other than that, very useful post tom lol

roastbeef · 01-24-2019, 02:21 PM

I've ran the same k&n on my desert truck for ten years now. All it sees is dust, and the inside of the filter is always clean. They are good filters. Most of the problems people have with them is when they clean them, they over oil.

Richbot · 01-28-2019, 10:21 AM

I have yet to re-oil mine after two cleanings and it is still pinkish

Also, I found 8 leaves and 3 bees last time I pulled it off so it's doing an excellent job of keeping animals and large plants out of the engine

storM3trooper · 03-16-2019, 12:54 AM

Quote:

Originally Posted by randrews15

I've used them in several cars with no issues. The gain is minimal but you can certainly feels a little pep out of the motor. Having said that, in my M I have the Macht Schnell stage 2 intake and there was a much bigger bump in the feeling and sound out of the motor. I'd stick to the drop in filter, as I don't care for the looks of K&N's performance kits at all.

I have the Macht Schnell too I love it

DavidZ · 04-19-2019, 11:17 AM

I get a K&N drop-in within the first month of ownership of all my cars, just because. Never had any issues.

mapster37 · 04-19-2019, 11:40 AM

i installed active Autowerke green drop in filter. definitely louder intake sound, and mpg's increased as well. went from 12.1 to 13.5mpg. would definitely recommend!!

Ximian · 04-29-2019, 02:00 PM

Each look at my air filter reaffirms my belief that less restrictive filters aren't a good idea for daily drivers. The top right filter spent about a year in the car, the one next to it about 4 months, and the left one is brand new.

All the small particles in the filter after two months of use (about how often I clean out the filter) -

Leonardo629 · 04-30-2019, 11:02 PM

is that dirt and gravel on your hood? OMG

roastbeef · 05-01-2019, 08:36 PM

so, after you shook out the filter onto your hood- did you think to yourself, "why did i do that?"

Ximian · 05-07-2019, 08:46 AM

That was done on the hood of the winter beater. It's also where I store my brake fluid and sand paper.

e903er · 12-18-2019, 11:00 AM

Quick question - Per K&N website, there are 2 options available for the e90/92 M3 - E-1994 (US models) and E-2994 (non-US models). The only difference seems to be the height - E-1994 is 8.438" and E-2994 is 8.938".

Anyone knows the reason behind the difference?

There are quite a few reviews on Amazon for E-2994 in the US and the non-US filter is cheaper as well. (https://www.amazon.com/gp/product/B0...k_ql_qh_dp_hza)

01-18-2019, 10:07 PM	#1
pcohen15 Lieutenant 380 Rep 533 Posts Drives: 2013 F10 M5, Singapore Gray Join Date: Jun 2016 Location: Scottsdale, AZ iTrader: (0)	Anybody using K&N air filters? Good experience? I'm interested in knowing how forum members who use K&N air filters like them. (Just the drop-in filters, not the housings.) Notice any difference at all from stock? Have you cleaned and reused them? Did you buy the K&N cleaning kit? Would you recommend? Thanks! __________________ 1972 Bavaria> 1973 3.0Si> 2013 328i> 2009 E92 M3> 2013 F10 M5: Singapore Gray over Sakhir Orange, Executive, Driving Assistance, B&O
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01-19-2019, 05:10 AM	#2
randrews15 Lieutenant 289 Rep 553 Posts Drives: 2012 E93 M3 Le Mans Blue Join Date: Nov 2012 Location: Parrish, FL iTrader: (1)	I've used them in several cars with no issues. The gain is minimal but you can certainly feels a little pep out of the motor. Having said that, in my M I have the Macht Schnell stage 2 intake and there was a much bigger bump in the feeling and sound out of the motor. I'd stick to the drop in filter, as I don't care for the looks of K&N's performance kits at all.
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01-19-2019, 06:07 AM	#3
TomHudson Major 658 Rep 1,118 Posts Drives: 2011 E90 M3 Join Date: May 2015 Location: Toronto iTrader: (0)	I’ve used them in forced induction cars, with excellent results. This car has the Dinan intake, same type filter. I like the convenience of cleaning it myself and not having to order and change the paper element.
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01-19-2019, 10:41 AM	#4
IamFODI Lieutenant 366 Rep 404 Posts Drives: 2008 E90 M3 6MT Join Date: Dec 2018 Location: SE PA iTrader: (0)	Like most OE filters these days, BMW's are good enough that unless you're installing a filter with much more surface area (and sometimes even then), you should expect any filter that flows more to also let in more dirt. Food for thought, especially as the stock filter isn't a major point of restriction. More dirt is a tall price to pay for basically no real gains. For an oiled filter, there's the additional challenge that the cleaning and re-oiling has to be done perfectly or you'll end up with reduced flow, increased dirt ingress, excess filter oil in your intake, or some combination thereof. I can see the convenience argument. Personally, I'd rather tack an OE filter onto my FCP Euro parts order every once in a while, send the old one back with my next return to them, and save myself the time and effort of cleaning and re-oiling. All-in-all, for a custom intake on a high-HP car that doesn't see a lot of miles, I can see going with a K&N. But for an OE-replacement filter on a stock intake in a regularly driven car, I'd stick with OE. Last edited by IamFODI; 01-19-2019 at 05:58 PM..
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01-19-2019, 04:12 PM	#5
joe6mt Private First Class 65 Rep 131 Posts Drives: 2012 M3/6MT Join Date: Nov 2016 Location: Illinois iTrader: (3)	I have the drop in K&N air filters used for about 2K miles. The gain is very minimal, but you can defi felt the induction noise a tap lounder than OEM filter. I wouldn’t re-oil them, when time to replace them just get a new one. I had the Eventuri intakes, is gain and induction noise is nice and a day diff thou. __________________ 2012 E92 M3 w/ Competition Package
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01-19-2019, 05:35 PM	#6
pcohen15 Lieutenant 380 Rep 533 Posts Drives: 2013 F10 M5, Singapore Gray Join Date: Jun 2016 Location: Scottsdale, AZ iTrader: (0)	Thanks for the feedback. At 5-7k a year, I think I'll go the FCP/OEM replacement route. __________________ 1972 Bavaria> 1973 3.0Si> 2013 328i> 2009 E92 M3> 2013 F10 M5: Singapore Gray over Sakhir Orange, Executive, Driving Assistance, B&O
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01-24-2019, 12:08 PM	#8
Z K Major General 1889 Rep 5,506 Posts Drives: E90 M3, G20 M340i Join Date: Jul 2011 Location: San Francisco iTrader: (3)	I have been using the Active Autowerke Green filter. Besides needing to clean and re-oil it every oil change or so, it has been working good. Oiled filters don't affect anything on the car as the M3 doesn't have a MAF sensor. From bad past experiences, I would not run a oiled filter on any MAF equipped car. Lots of tar-like black build up from track use though. The cleaner can't clean this stuff off - I have to scrub it with a brush. I don't think this would be any different with any air filter.. it's just track life. __________________ Auto Detailing Enthusiast!
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01-24-2019, 01:45 PM	#11
Richbot Major General 2759 Rep 5,484 Posts Drives: Jerez Black E90 Join Date: Sep 2007 Location: STL iTrader: (5)	lol yeah the E36M didn't have a square foot of intake in the front bumper a foot off the ground aiming everything down near road level, like dust kicked up from other cars, pushing it through a duct aimed directly at the bottom of the air filter. It draws air from behind the front splash guard (aftermarket) and or the engine bay, uses a panel filter, etc. not the same at all and this is the only car I've had that fouls filters like this it's amazing how gross they get on the bottom. but other than that, very useful post tom lol __________________ Last edited by Richbot; 01-24-2019 at 02:00 PM..
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01-24-2019, 02:21 PM	#12
roastbeef Lieutenant General 11585 Rep 12,724 Posts Drives: E92 M3 Join Date: Nov 2010 Location: Orange County, CA iTrader: (4)	I've ran the same k&n on my desert truck for ten years now. All it sees is dust, and the inside of the filter is always clean. They are good filters. Most of the problems people have with them is when they clean them, they over oil. __________________ Instagram; @roastbeefmike
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01-28-2019, 10:21 AM	#13
Richbot Major General 2759 Rep 5,484 Posts Drives: Jerez Black E90 Join Date: Sep 2007 Location: STL iTrader: (5)	I have yet to re-oil mine after two cleanings and it is still pinkish Also, I found 8 leaves and 3 bees last time I pulled it off so it's doing an excellent job of keeping animals and large plants out of the engine __________________
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04-19-2019, 11:17 AM	#15
DavidZ Lieutenant 83 Rep 399 Posts Drives: '11.5 E90 M3 6MT Join Date: Apr 2011 Location: Kensington, MD iTrader: (1)	I get a K&N drop-in within the first month of ownership of all my cars, just because. Never had any issues. __________________ -David
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04-19-2019, 11:40 AM	#16
mapster37 Captain 362 Rep 923 Posts Drives: F80 Join Date: Sep 2018 Location: Davie iTrader: (2)	i installed active Autowerke green drop in filter. definitely louder intake sound, and mpg's increased as well. went from 12.1 to 13.5mpg. would definitely recommend!!
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04-29-2019, 02:00 PM	#17
Ximian . 1916 Rep 1,878 Posts Drives: E92 M3 Join Date: Oct 2016 Location: MN iTrader: (1) Garage List 2011 BMW M3 [0.00] 2021 BMW M3 [0.00]	Each look at my air filter reaffirms my belief that less restrictive filters aren't a good idea for daily drivers. The top right filter spent about a year in the car, the one next to it about 4 months, and the left one is brand new. All the small particles in the filter after two months of use (about how often I clean out the filter) -
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04-30-2019, 11:02 PM	#18
Leonardo629 Lieutenant Colonel 168 Rep 1,792 Posts Drives: 2013 M3 Coupe Join Date: Sep 2006 Location: Taiwan iTrader: (10)	is that dirt and gravel on your hood? OMG
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05-01-2019, 08:36 PM	#19
roastbeef Lieutenant General 11585 Rep 12,724 Posts Drives: E92 M3 Join Date: Nov 2010 Location: Orange County, CA iTrader: (4)	so, after you shook out the filter onto your hood- did you think to yourself, "why did i do that?" __________________ Instagram; @roastbeefmike
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05-07-2019, 08:46 AM	#20
Ximian . 1916 Rep 1,878 Posts Drives: E92 M3 Join Date: Oct 2016 Location: MN iTrader: (1) Garage List 2011 BMW M3 [0.00] 2021 BMW M3 [0.00]	That was done on the hood of the winter beater. It's also where I store my brake fluid and sand paper.
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12-18-2019, 11:00 AM	#21
e903er Enlisted Member 2 Rep 32 Posts Drives: e90 328i pre-LCI Join Date: May 2017 Location: Ann Arbor, MI iTrader: (0)	Quick question - Per K&N website, there are 2 options available for the e90/92 M3 - E-1994 (US models) and E-2994 (non-US models). The only difference seems to be the height - E-1994 is 8.438" and E-2994 is 8.938". Anyone knows the reason behind the difference? There are quite a few reviews on Amazon for E-2994 in the US and the non-US filter is cheaper as well. (https://www.amazon.com/gp/product/B0...k_ql_qh_dp_hza)
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