DeTh

Has anyone had any experience with K&N vs OEM filters? Will the oil in the K&N filter damage the MAF sensor?
Also effectiveness of K&N vs OEM (Mann)?

rapidoxidation

K&N (aka a rock filter) is best left in the box on the retailer's shelf. It isn't the oil in a properly maintained K&N rock filter that will damage the engine, it is all the sunlight you can see through it. They don't filter small particles very well at all.

DeTh

I feel like I've seen opinions from two opposite ends of the spectrum. Some swear by them, and have been running them for the past 15 years with no problems, and other people despise them for the extra particles that they let through.
I don't live in a dusty place at all (Florida), and 99% of my driving is on paved, nice roads. What would be some possible downsides to running a K&N filter (ex: the damages that would occur to the engine), and how long would they take to occur?

bmwpowere36m3

There’s no upside to using them either…. probably can buy 16 years worth of factory filters for 1 K&N.

S-Prihadi

Your air to fuel mix is ECM managed. OE filter has surplus capacity up to a point a filter get dirty X percent.
No extra air can improve your engine , unless the fuel mapping takes into account the extra air ( plus extra fuel ) and if only the proper mix ( AFR ) can be achieved.
Standard engine with engine internal un-touched aka stock form, is never botteneck-ded by OE filter.

Don't waste your money and don't introduce fine particles into combustion chamber, if you plan to keep the engine healthy for long term.

DFWdude

I have the similar driving conditions here in Texas. But dusty is a relative term... Southern climates get inundated with other particulates, including seasonal pollens that cover cars with a yellow haze. If you think you live in crystal clear air, you're kidding yourself.

You sound determined to buy the K&N. Go ahead. Just be aware that K&N is universally disliked on these forums. As bmwpower notes two posts above, the OEM filter is way cheaper to buy than the K&N. I am not an OEM advocate on all things MB, but there's no logical (or beneficial) reason not to use OEM or OEM-equivalent engine filters.

Finally, I used a K&N filter once, several cars ago. The procedures required to service them are tedious, messy and time-consuming, even for this shadetree mechanic. I have since found I have better things to do with my time.

Arrie

I used K&N for a short time in my Crown Victoria as it was a real race car and I wanted more power out of that 5 L engine that spit a spark plug on me.

Seriously, I did use K&N in that car but for all the trouble of maintaining the filter correctly I tossed it after the first filter wash-and-oil service. Way too much trouble for getting more air flow in the engine. What is that air flow increase as I hardly drove that car for the maximum performance?

These modern cars don’t benefit from more open filter unless you really want to pull the last ounce of power out of the engine and this goes only with the NA engines. With turbos the filter does not give any benefit at all as the turbo creates the engine intake pressure that is controlled to a certain maximum pressure. Getting more air to the intake of the turbo just means more air is wasted before the engine intake.

What comes to filtering quality it usually is that when you get air flow easier thru the filter it means it does not filter as well. K&N says the oil in the filter media attracts particles and filtering is good while at the same time the filter is more open for air flow. Well, for that oil to work like that it must be very carefully maintained and for that I think you should do the filter cleaning and oiling way more often than what the instructions say. I think (may remember wrong) it was every 5000 miles. In 5000 miles the oil in filter is gone and it will not attract anything and you end up running a way more open filter for long distances between filter service.

K&N filters may make sense for some type or race car engines (no turbo) when the filter is serviced after each race, like rest of the car also is serviced after each race.

For normal car use K&N is waste of money and time in my opinion.

Gazwould

K&Nooooooooooooooo

kajtek1

The chart above should tell it all.
If you want better performance - delete filter like the racers do
..... and rebuild engine every year, or every race.
Beside K&N allowing dust to enter the engine there is lot of BS about "cold air intake" on their site.
Most of their application sucks hot air from engine bay, when MB intakes takes cold air from front of the grille.

Left Coast Geek

If I'm looking at a used car and see *any* signs of a K&N filter, I'm outta there.


The Mann OEM Mercedes air filter for a M276 E350 is around $32,, and Mercedes recommends replacing it every 50K miles or 5 years. nuff said?

kajtek1

I actually installed filter minder on my previous MB (still have 1 in the box for latest purchase).
Driving 90,000 miles in "Clean air California" I sold the car with the only filter I replaced and still showing in green zone on the gauge.
Filter minders sell for about 10 bucks. They can save you quite a few dollars on even on $32 filters, when set of filters for 6 cylinder diesel is closer to $100
Not to mention quiet mind when you can see your filter is still clean.
That said, 1000 miles in Baja clog my filter in the past.

Gazwould

I plugged in my iCarsoft and it told me that the air filter was 8% full !!

Left Coast Geek

hah, my 2002 F250 diesel pickup came with one of those, and its wired to a light in the instrument panel. afaik its factory original.

kajtek1

All my Superduties come with filter minder from the factory.
The 1999 model did not have light hook up, but still did the job. Not like you have to check your air filter on weekly bases.
Now Gazwould, how did you get the menu on iCarsoft?
I gave up on this scanner lately, as it was giving me bogus data, but will have to check it again

fc3

I would not use K&N filters on any car or truck in lieu of the factory recommended paper element filter. There is not one advantage to the K&Ns. On the other hand, their filtering ability is, at best, questionable, and they are a pain to maintain.

That said, I have a pair of K&N air filters on my boat's main engines. Gasoline marine engines are not built with air filters. Instead they have back flame arrestors that prevent a flame from escaping the intake tract of the engine in the event of a backfire. Even port injected EFI engines are required to have back flame arrestors. Since K&N has U.S. Coast Guard approved filters with back flame arrestor features, I use them on my boat to deal with the dog fur problem. My dog's fur would clog the OEM back flame arrestors. The fur brushes off the K&Ns. But cleaning the K&Ns when they get dusty / dirty is a pain!

Darel

K&Ns are for guys who want to DO MODZ so they have something to make a TikTok about to show girls how handy they are.

BenzV12

I would stick to OEM no matter what

Gazwould

All that filtration...

juststeve

so it's no on the lime green wiper blades..got it