[F30104]

Hey everyone, I am thinking about dropping in the K&N air filter...Website promises slightly more HP and Fuel efficiency. What are your thoughts on this? Pros and Cons?

edit: I have a 2015 320i

thanks!

[sspade]

Originally Posted by F30104

Hey everyone, I am thinking about dropping in the K&N air filter...Website promises slightly more HP and Fuel efficiency. What are your thoughts on this? Pros and Cons?

edit: I have a 2015 320i

thanks!

Do it. Don't expect any noticeable HP gains but rest assured that your engine will be breathing better than it is with a paper filter. You'll be in the same position as those who spent hundreds more on an aftermarket intake (except maybe not as loud).

Do yourself a favor and pick up an oil/cleaner kit on eBay for $15 shipped (from ECS Tuning) and youll be good to go for a long time.

I clean and oil mine every oil change (5k miles).

[sspade]

Also... you might want to look into the aFe scoop. Mounts right behind the right kidney grille and directs more air into the intake system.

If you play your cards right... you can get the filter, scoop and oil/cleaning kit for about $100.

No brainer in my opinion.

[Kafkaesque328]

it won't make much difference on stock power except 'maybe' hearing a little more intake noise but if you were pushing JB stage 1 or beyond, it might make a difference. The thing is that the airbox design on the F30 just isn't really restrictive so the different filter element won't really matter. There have been dynos etc. of drop in air filters and they do close to nothing.

[BMWinAZ]

Not a fan at all! If you over-oil the filter after a cleaning it can mess with the Mass Airflow Sensor. Also, I think the cleaning process itself is just an unnecessary and fussy waste of time compared to the simple swap of the OEM paper filter. In addition, I have read somewhere (can't recall where) that the oiled filters are not that effective in keeping small particles at bay in dry, dusty climates. Furthermore, there is contradictory info out there as to the gain caused by these filters, seems mostly negligible in stock cars that are daily driven in normal traffic.

[Busa1]

I would get the AFE Pro-Dry S air filter instead of the K&N. I heard the same thing as mentioned above about too much oil applied on the filter can mess with the MAF sensor.

[Billfitz]

Originally Posted by F30104

Website promises slightly more HP and Fuel efficiency.

Of course they do, otherwise why would you want to buy one? If you want as much HP and fuel efficiency possible don't use any filter. You'll destroy your engine, but at least you had fun while it lasted. You can get some minor gains with a filter that allows more airflow, but the only way to do that is by also allowing more particle flow, which reduces engine life.

[F30104]

Originally Posted by Billfitz

Of course they do, otherwise why would you want to buy one? If you want as much HP and fuel efficiency possible don't use any filter. You'll destroy your engine, but at least you had fun while it lasted. You can get some minor gains with a filter that allows more airflow, but the only way to do that is by also allowing more particle flow, which reduces engine life.

Thanks for the input!

[sspade]

Not disagreeing with any of the commenters on this thread but would like to say:

I have never had an issue with over oiling my filter and messing with the MAF sensor.

I usually take care of filter clean and oil first and then let it dry in the sun while I change the oil. By the time I have everything buttoned back up, the filter is ready to go.

[F30104]

Originally Posted by sspade

Not disagreeing with any of the commenters on this thread but would like to say:

I have never had an issue with over oiling my filter and messing with the MAF sensor.

I usually take care of filter clean and oil first and then let it dry in the sun while I change the oil. By the time I have everything buttoned back up, the filter is ready to go.

Yea, I think I'm going to give one a try. I did look it up and directions said to not over oil and let completely dry.

[paul e]

Well....over at the Miata forum...and these guys are just as committed as those here...an actual engineering test was done on air filters, as the same K&N question comes up.
Result....the OEM air filter does just as good a job.
Meanwhile....on the Triumph Bonneville forum...also a committed bunch....an aftermarket supplier of high performance air filters tested his against others.
Result....his “won” by about 3% over the stock one, and the stock bested all the others.

[XutvJet]

Don't run an oiled air filter. If you must have an aftermarket filter, get a dry one.

[F30104]

Originally Posted by paul e

Well....over at the Miata forum...and these guys are just as committed as those here...an actual engineering test was done on air filters, as the same K&N question comes up.
Result....the OEM air filter does just as good a job.
Meanwhile....on the Triumph Bonneville forum...also a committed bunch....an aftermarket supplier of high performance air filters tested his against others.
Result....his "won" by about 3% over the stock one, and the stock bested all the others.

Wow! That's good info! So basically it wouldn't make much of a difference going to a K&N. Only benefit I see, itd be nice to just buy ONE filter and be done. Not having to replace it seems like a win.

[sspade]

Originally Posted by paul e

Well....over at the Miata forum...and these guys are just as committed as those here...an actual engineering test was done on air filters, as the same K&N question comes up.
Result....the OEM air filter does just as good a job.
Meanwhile....on the Triumph Bonneville forum...also a committed bunch....an aftermarket supplier of high performance air filters tested his against others.
Result....his "won" by about 3% over the stock one.

So in effect...

You are saying that K&N Engineering has been bullshitting people since its inception in 1964?

And people just keep buying their overpriced filters that provide absolutely no value?

I wish I could come up with a business idea like that!

[paul e]

Except you still have to take it out to clean and re-oil.

[paul e]

Originally Posted by sspade

So in effect...

You are saying that K&N Engineering has been bullshitting people since its inception in 1964?

And people just keep buying their overpriced filters that provide absolutely no value?

I wish I could come up with a business idea like that!

I’m not saying anything, I am relating 2 instances of comparison.

[F30104]

Originally Posted by paul e

I’m not saying anything, I am relating 2 instances of comparison.

Well on my way to auto part store. I just finished a complete tank of gas. I'll compare mpgs for the hell of it with the new filter.

[Billfitz]

Originally Posted by sspade

So in effect...
You are saying that K&N Engineering has been bullshitting people since its inception in 1964?
And people just keep buying their overpriced filters that provide absolutely no value?
I wish I could come up with a business idea like that!

The purveying of snake oil is hardly a new concept. The oldest commonly used term related to it is 'caveat emptor', and the Romans were by no means the first to issue warnings to consumers that truth in advertising is an oxymoron.

[sspade]

Originally Posted by Billfitz

The purveying of snake oil is hardly a new concept. The oldest commonly used term related to it is 'caveat emptor', and the Romans were by no means the first to issue warnings to consumers that truth in advertising is an oxymoron.

Understood and agreed BUT...

Do we really think that hidden behind the walls of K&N Engineering's manufacturing facility lie a team of uneducated illegal immigrants gluing paper and rubber together, sticking it in a fancy box with a logo and hoping for the best without any engineering, quality or testing guidelines?

I would have to believe that they are genuinely testing and engineering a quality product that meets ISO standards as the claim they are. Not to say everyone in the business is doing this but can we at least have a little faith in humanity for once!?

[alohasurftoad]

i have had a k&n and unifilter(foam flows better than gauze) in the past. no objective testing. subjectively(butt dyno), found both to make slightly more noise. power gains, if any, were insignificant.

with both filters long gone, i just recently threw out the cleaner and re-oiling spray for both which was on the shelf for years, and thought to myself what a waste of money and time, and how they get you with all that marketing.

having said all that and "knowing better", getting a high flow drop-in still occasionally crosses my mind. if i were to, i'd just get a dry filter. clean it with low pressure air (reverse flow) and/or vacuum it. wash it if it was really bad.

if you want to try something i'd just get this ebay one. 1/3 the price of k&n and 1/4 the price of afe dry, probably works the same. if it's junk, it was just $18.

https://www.ebay.com/itm/Reusable-Bl...cAAOSwEZdZ8vug

if you have more money to waste and want to try the name brand stuff

https://afepower.com/afe-power-31-10...y-s-air-filter

https://www.ecstuning.com/b-pipercro...er/pp1885~ppc/

https://www.hpashop.com/HPA-F30-F32-...Air-Filter.htm

i'd monitor and clean the foam ones more often as there are more holes and less material. this ain't rocket science...

[Billfitz]

Originally Posted by sspade

can we at least have a little faith in humanity for once!?

To quote Mr. Reagan, "Trust, but verify". In this case verification would come in the form of 3rd party testing that validates the claimed results.

[BEAR-AvHistory]

Originally Posted by Billfitz

To quote Mr. Reagan, "Trust, but verify". In this case verification would come in the form of 3rd party testing that validates the claimed results.

Would not waste my money on one for a BMW.

http://nicoclub.com/archives/kn-vs-oem-filter.html

The ISO 5011 Standard (formerly SAE J726) defines a precise filter test using precision measurements under controlled conditions.