Any benefit to K&N filters on a stock X5M?

[Rez90]

I was looking over the wives car today and pulled the air filters. They definitely need to be replaced and was curious if the K&N replacements offer any benefit. I've seen that on some stock cars they actually cause a leaner AF Mixture causing CEL's and whatnot but i was curious if anyone here had any experience or insight.

Also...what are the white filters behind the air filters? They also looked pretty cruddy.

Thanks in advance.

[jjstecher]

My guess is they give you a few hp max. I've never seen any filter in all my dyno days get dropped in and produce a massive amount more HP on any newer car. Old stuff sure when the base filters were garbage but now all the systems are pretty optimized.

Might give you more intake sound however and you can just wash them, oil them and drop them back in. That's why I buy them.

[windtendo]

From what I've read. On here, dry filters are the way to go. I personally haven't changed mine just because of the minimal gain they offer. BMC air filters seem to be the default filter to go with if you want to go aftermarket as they don't require oil.

[mitch808]

Nothing perceivable at all using your butt dyno. If anything, oiled filters are more trouble than they are worth..

[theaudir8fan]

while i know some holds the opinion that K&N filters are terrible, but I know many people on and off the forums that uses them without any issues or concerns. Of the people that I talked to, no one says the filter makes any performance differences, but since the filters needs to be replaced anyways, K&N is a good alternative compared to OEM. Also do note that many aftermarket performance stores such as Underground Racing uses K&N products and non have had issues as a result of the filter so I don't think it is as bad as many says believes

[mitch808]

There is nothing wrong with K&N per say. However, if over oiled they will foul intake sensors like the MAF which is highly sensitive. Sometimes it's cleanable, other wise you're looking at a multi hundred dollar replacement.

Otherwise, a STOCK K&N filter does nothing perceivable to anyone. Change the filter size to a cone style filter, where flow actually increases, then we're talking. Change the intake piping where it actually increases velocity, then with a proper cone filter, you'll see gains.

[hd2000fxdl]

Been down this road before and learned a thing or 2 from some of the others around here. While I'll still use K&N on my Harley's and older vehicles, the new once like we have I'll just use a stock filter. Performance gains are not much if at all, while it's really not going to be an issue in 99.9999999% of the vehicles, the better flow does come many time with not as good filtering process. Additionally, a filter you oil can gum up and effect the performance of the MAF that can then degrade performance.

Will they in real life hurt your vehicle, probably not, will they add power, in theory maybe, can you feel it, probably not, can you hear a difference. maybe but what's that net you.

Harry

[Rez90]

Well...pulled the stock filters tonight along with the carbon filters and installed the K&N's.

This could be due to the stock filters being FILTHY but there is definitely a difference. The truck is snottier and more responsive. There's no doubt about it.

I always thought the truck felt a little choked and i even mentioned to my mechanic at my end of warranty check.

Granted we're not talking a huge difference at all...but the truck definitely woke up from the change. would a change of stock filters have done the same....maybe. But in whatever case i'm very happy.

I took the truck for a spin around the block and all i could think to myself after i let off the gas every time was...."Now the truck feels like it needs a tune..."

The bug.....has bitten.

Someone talk me out of calling Velos tomorrow......

[theaudir8fan]

Good to know that you are happy with the K&N filters, altho I think the main reason for the noticeable difference is caused by the charcoal filter delete.

Call velos, they got some great stuff for the M, I'm very happy with their tune

[x5m Fritz]

Dear BMW community,

I know the thread is a bit older now, but I wanted to ask the question about K&N air filters and the bmw X5M again:

- who has had their own experience with such a K&N exchange filter?
- Because I have a new filter like this lying here, it is already pre oiled. Now I'm afraid that it has already been oiled too much (see photos), what do you think?


Best regards from Italy,
x5mFritz

[GSX-Ryan]

What makes you think it has been over-oiled?

[TwinSnailz]

Your engine comes oily naturally from intake to the engine head. Pull the intake air duct, that is connected to the turbo, its full of oil.
A bit on the filter is nothing.

[S.W.G.]

No. There is nothing worthwhile on this platform unless you're upgrading turbos.

[Sophisticated Redneck]

The S63 doesn't use MAF sensors so even if the filters are over-oiled, it won't cause any issues and as Twin mentioned, the s63/n63 engines are about as oily as it gets this side of a diesel so the engine itself won't even notice.

[Thecastle]

The air filters make little if any performance difference and let a lot more particulate matter through that increases engine wear. I’d skip these, for the small gains you get don’t seem worth the increased engine wear. Spend money elsewhere

[eDubz]

I've had them installed for about 4K miles. Haven't noticed any difference.

[x5m Fritz]

Wow thx people

for all these messages!
Some statements help me a lot and I have to say that you get really helpful and technically valuable comments here, very mutch bedder then in other forums!

thx 4 this,
and after then, i will also report my further experience with the K&N filter, maybe i try it for a 100 miles....

[pearlpower]

This question gets asked on every forum out there, and the answers are always the same. From people with no clue that should not even comment, to those with experience. Best to decide on your own based on the available info.

[Thecastle]

Originally Posted by pearlpower

This question gets asked on every forum out there, and the answers are always the same. From people with no clue that should not even comment, to those with experience. Best to decide on your own based on the available info.

I've watched the engineering explained videos before. He is good at exploring one dimension of performance air flow, but neglected to look at filtering ability.

There is no free lunch and always trade offs. Generally the less restrictive the filter of the same size the less able it is in removing particulates. The more particulates ingested in the engine the faster it wears out. The better the filters ability to remove particles the greater the pressure drop/restriction to airflow.

The project farm video did both filter performance and particulate performance including k&N.

Agreed this question always comes up. Just like hot air intakes and intercooler "upgrades". Of course they can make a difference in the right application, but most people don't understand the trade off and right application.

[x5m Fritz]

Thanx for the very technical and interessting videos, it seems to be a good research..
And also thanx for your experience, it is clear to me anyway that this K&N filter not improves some big noticeable performance. My main concern is whether the exhaust sound could get better / a little deeper ....
I will install the filter and then compare it - and report here.


By the way, and i think it is very unfortunate that the RK- air intakes are so expensive, this would be mi first choice....


Thanks meanwhile and regards,
x5m fritz

[pearlpower]

Originally Posted by x5m Fritz

Thanx for the very technical and interessting videos, it seems to be a good research..
And also thanx for your experience, it is clear to me anyway that this K&N filter not improves some big noticeable performance. My main concern is whether the exhaust sound could get better / a little deeper ....
I will install the filter and then compare it - and report here.


By the way, and i think it is very unfortunate that the RK- air intakes are so expensive, this would be mi first choice....


Thanks meanwhile and regards,
x5m fritz

A panel filter will not alter the exhaust sound - at all. FYI, I have run KNN is well over 30 vehicles.