[sinbad4]

I had previously noted that the K&N Air Filter for the MY2020 X3M40i was different than the 2018/19 model years. Not much.. but enough so it won't work. I've been impatiently waiting. My BMW SA tells me the part# is 13-71-8-581-691. I was hoping to match with Z4 or other model, but didn't have much luck.

Last week I wrote to K&N Support. They said they have no official part; but it said: BMW part number 13-71-8-581-691 cross references to K&N air filter 33-3134 linked: https://www.knfilters.com/33-3134-re...ent-air-filter

I was pleased to hear. Ordered directly. ($70) Just delivered. Just installed.

w00t!! It works! Perfect fit!

Selling my old one cheap, if interested (local pickup only). https://x3.xbimmers.com/forums/showt...4#post25679494

I am big believer in K&N filters and have used for years. I always heard 5-10hp.. that was on lesser cars. Performance Engineering did some tests.. they saw 3.6% increase in performance. That would be about 14HP on the 2020 M40i.

[John26830]

Oil treated..? Any issues with sensors possibly?
I have used K&N in my other cars & they do make a superior filter

[mariopl]

How about 30i? Do they produce a filter for 30i and does it provide any performance boost?

[chrisk03]

Originally Posted by mariopl

How about 30i? Do they produce a filter for 30i and does it provide any performance boost?

33-3079 = K&N air filter model number on the USA website for a 2019 X3 30i. Probably a minimal boost, but I've always liked these filters for providing a bit better throttle response.

FB929/20 = BMC also makes an air filter for the 30i.

[suby01]

Great work. Great find. Thank you X's a 1000 for sharing this with us.
Now were still searching to cross reference an intake part #.

[GoodGuyAvi]

Installed too like a month ago. And I feel a big difference.
Did you saw our original filter??!?! I guess its made for off road !?!
Maybe on other cars you don't feel difference because stock filter its kind of the same....but in our case our stock is 1.3 times fatter.

[suby01]

Originally Posted by AvetNY

Installed too like a month ago. And I feel a big difference.
Did you saw our original filter??!?! I guess its made for off road !?!
Maybe on other cars you don't feel difference because stock filter its kind of the same....but in our case our stock is 1.3 times fatter.

You mean you also installed the KN?

[GoodGuyAvi]

Originally Posted by suby01

You mean you also installed the KN?

Yes correct

[Sorry About That]

Just installed a K&N filter in my 2020 X4 G02 thanks to the info provided by OP. It was a perfect fit. Thanks. For anyone wanting to do this you will need a T25 torx bit and extension for the 6 bolts on the air filter housing, a 16-point 11mm socket and a 16mm socket to remove the strut braces. I also wrapped the strut braces in carbon fiber vinyl while I was at it.

[sinbad4]

Originally Posted by Sorry About That

Just installed a K&N filter in my 2020 X4 G02 thanks to the info provided by OP. It was a perfect fit. Thanks. For anyone wanting to do this you will need a T25 torx bit and extension for the 6 bolts on the air filter housing, a 16-point 11mm socket and a 16mm socket to remove the strut braces. I also wrapped the strut braces in carbon fiber vinyl while I was at it.

Pics of wrapped strut braces, pls.

[Jeepersjoey]

Did you see my matte black painted struts?

Also...don't drop one of those bolts when you are removing the air filter, or the torx bit, or the socket you use because you dropped the torx bit. You will need to remove 15+ bolts to remove the plastic under the car just to get them all back.

No idea why I would know this...

Paul

[IslandDriver]

Originally Posted by Jeepersjoey

Did you see my matte black painted struts?

Also...don't drop one of those bolts when you are removing the air filter, or the torx bit, or the socket you use because you dropped the torx bit. You will need to remove 15+ bolts to remove the plastic under the car just to get them all back.

No idea why I would know this...

Paul

Mehhh, the filter cover is perfectly secure with one or two bolts less...

[Oldguysrule]

I personally don't think an air filter is going to add very much in the way of performance without unrestricting the exhaust by a similar amount. I would hope that if a different air filter would provide even a 10HP boost, some engineer at BMW would have spec'd it? Don't know.

[suby01]

Originally Posted by Oldguysrule

I personally don't think an air filter is going to add very much in the way of performance without unrestricting the exhaust by a similar amount. I would hope that if a different air filter would provide even a 10HP boost, some engineer at BMW would have spec'd it? Don't know.

You can hear the turbski a lot more under WOT. I doubt that it adds HP

[Sammy_V]

Thanks for the update sinbad4

Did you, or anyone, notice a difference in sound ?

Thanks
Sam

[suby01]

Originally Posted by Sammy_V

Thanks for the update sinbad4

Did you, or anyone, notice a difference in sound ?

Thanks
Sam

Literally see my post above yours. Yes you can hear the turbo spool now.

[Dandle]

This video is worth a watch, it appears the gains from the K&N are because it's not actually a very good filter and with such small gains is it worth it? Personally I stick with the OEM filter but change it at each oil change rather than every other as per the service schedule.

[heavyD^2]

I'm smitten with the OEM filter as it does everything required of an air filter (remember the sole purpose of a filter is to filter out dirt and other airborne particles). Keeps dirt out of the intake as required by BMW engine engineers and doesn't inhibit my S58 engine from making over 500 hp.

[sinbad4]

Originally Posted by Sammy_V

Thanks for the update sinbad4

Did you, or anyone, notice a difference in sound ?

Thanks
Sam

Yes, sound difference. Like Suby01 suggests; you can hear the turbo spin up a little easier now.

I prefer the drop in as opposed to the cylinder filter solution some people use primarily as the drop in retains the cold air path. I suspect the guys going with the cone / cylinder solution where they removing the top of their airbox hear the turbo even better - which I like - but then have hot under hood air issues / reduced performance.

[sinbad4]

Originally Posted by heavyD^2

I'm smitten with the OEM filter as it does everything required of an air filter (remember the sole purpose of a filter is to filter out dirt and other airborne particles). Keeps dirt out of the intake as required by BMW engine engineers and doesn't inhibit my S58 engine from making over 500 hp.

2.5-3.5% difference on HP and torque. 2.25% faster 0-60. By far the best $ / power mod you can do.

The only caveat to using a K&N (or any other oil based filter) is high dust / dirt environments. If I lived on a dirt road; or drove on dirt regularly; I would stay factory.

[fricfracfrank]

Do the x3s have a permanent charcoal filter in addition to the drop in?

[suby01]

Originally Posted by fricfracfrank

Do the x3s have a permanent charcoal filter in addition to the drop in?

No