Hey guys,

Basically I have seen a lot of W204 owners but K&N air filters on their rides, the reviews on amazon look really good. However, I have read they considering they let in more air, they thus let in more debris and other contaminants to your engine. Basically have any of you had problems with your engine because of the filters? Also those who have installed them have you noticed any performance and sound difference? Have you noticed any pedal response changes? I know the facelift model has different a different air filter that isn't a cone, but the idea is the same through and through. I'm most concerned whether or not it could cause damage and cut the life of my engine.

Thanks,
Nkucz

 

Yes.

I mean, come on, this is common sense. You want better short term performance? Don't use an airfilter.

Obviously they have to let in more air by reducing the amount of crap they stop. So short term, sure there's a gain. Long term - well, welcome to giving your car cancer.

Don't do it. Just b/c a bunch of BMW owners jump off a bridge...will you? :p

 

lol fair enough, thanks for your insight, I'll just order a new set of OEM paper filters xD

 

That's what I do...

I remember years ago I was looking into this. It was an air filter that was like a sponge/foam based, and there was a bunch of oil on it. I had it maybe 10 years ago. Apparently it works well in the dakar races.

But yeah...for a W204 C class Mercedes...yeah, stick to OEM. if you were getting 50+ hp more for risking your engine health, then great, but K&N? Well...if you're into unprotected sex with a hooker, knock yourself out...

 

Lol, I agree. It's not like the C300 is exactly a sports car or something, so minor performance increases are absolutely not worth it if they could potentially harm the engines longevity. This is my first car and I need it to last me!!! Guess I'll just wait till my Kleeman ECU upgrade to experience performance gains.

 

I don't know that K&N air filters increase your performance any degree that can be noticed in normal driving, nor do I think they are doing any harm to your engine either. They are just another choice out there to buy. They have been around a long time and do a great job marketing. If their products really harmed engines or reduced the useful life of them to any great degree that would have been exposed a long time ago.

 

There are studies that show more dirt and contaminants in engines or engine oil when using K&N filters compared to OEM paper filters. I'm not sure if this will hurt the life of the engine but I could only imagine it does based on common sense. It is a hard thing to prove however because you don't have a given as to how long the engine will last anyway...idk... just doesn't seem worth the risk.

 

My guess is that IF there would be any long term engine longevity difference it would be something like with an OEM air filter an engine will last 500,000 miles. With a K&N it will only last 499,000 miles. Is that a difference? Yes, of course. One ran longer using something else. However, does that difference mean anything in the real world or something to worry about? No, not at all because the difference is so small to be insignificant or could be traced to other variables. Or that one filters out smaller particles than the other. On the surface it sounds like the one that filters out the smaller particles is better, but they filter out stuff so small at at some point smaller doesn't make a difference because they are too small do do damage.

My personal opinion is you aren't taking a "risk" your engine is going to get damaged in a few years by using that so much as you aren't getting any benefit from paying the premium price.

 

Hmmm... interesting... I would have no problem paying for one as they aren't that expensive even if the performance benefit was minuscule. However, you can't just assume that out of 500,000 miles you would only lose 1,000 miles of engine life. That is just a guess at best and real world performance could potentially be much worse. We don't have a prolonged study of paper OEM filters vs K&N filters to determine this. All we have is studies that show up to 35% more contaminants or particles get through the K&N filters, which I believe could cause real harm. I guess the answer to the question is undetermined, because no one really knows.

Edit: do you run K&N air filters?

 

"Unlike many companies, our warranty for O/E replacement air filters and intake systems does extend beyond the replacement of a defective K&N part. For the original purchaser of the product, our warranty covers any engine damage or related costs incurred as a direct result of the use of a properly installed and maintained K&N O/E automotive replacement air filter or intake system on the specific vehicle for which the product was designed to be used by K&N. This includes reasonable vehicle repair costs directly related to an engine problem caused by the failure of a K&N product. Furthermore, we warrant that using our product will not result in a vehicle warranty denial. K&N will not be responsible for any indirect, consequential, special, contingent, or other damages not listed above."

This makes me more confident in potentially purchasing a K&N air filter...

 

I haven't gotten a K&N for the Mercedes, but have run them on pretty much every car I have had for over 25 years. Can't specifically say they transformed the performance of any of them, but I never had an engine issue with any of them. Drove most of them 150,000 miles or more. That includes an Alfa Romeo 164S, a couple of Saab 9/3s, a 9000 Aero and a 9/5, and a Jaguar X-type.

I just pulled those mileage numbers for the sake of argument to make the point that the difference in longevity would be insignificant. I have no idea what the actual numbers would be other than I think the mileage would be very very high.

The "studies" that show "UP TO 35%" difference in contaminants are more marketing than anything. It is interesting that you mention that the answer is undetermined and no one knows, yet you are swayed/scared by things you see on the internet so automatically err on the side of "caution". Then just as easily you feel at ease in looking at the K&N warranty. I'm sure they have that because they feel strongly about their product. On the other hand, I would bet that if you would put a claim in saying their product ruined your engine they would fight yo tooth and nail.

Again, I am not saying they are fantastic or so bad they will trash your engine. I think they are fine and I would not hesitate to use them. If there would be any harm to the longevity of the engine it would happen so far down the road that chances are the car would have gone through several other owners. Not many people even try and keep a car for 500,000 miles.

 

How does one improve air flow without sacrificing something like more crap in the engine? Hrmmm....

 

7. Some air filter companies tout their high filtration levels in the 99th percentile. Doesn't higher filtration mean a better air filter?
Not necessarily. 99% filtration efficiency is certainly a very good achievement. However, filter efficiency is just one statistic of filter performance which is measured (but is also the statistic most commonly published). The other air filter performance statistics measured are: capacity, restriction, and service life. These other factors reflect the amount of dirt the filter can hold, how easily air can flow through the filter, and how long the filter can be used before servicing. If one particular brand of filter consistently achieves 99%+ efficiency, it would be interesting to know if they also excel in the other performance areas, or are sacrificing one statistic to help increase another.

Given the fact that vehicle manufacturers do not publish specific filtration requirements for their vehicles, it is not strange that we find major, reputable filter brands offering replacement filters with efficiencies varying between 94%-99%. Many K&N filters achieve 98%-99% efficiency, in a product design that offers a longer service life, and much lower restriction than other brands of filters. So, a "better" air filter is really a judgement call, and varies by personal preference.

8. More airflow means you are letting more dirt through, right?
No, not at all. K&N air filters operate using a much different technology than other types of air filters. Most disposable filters are "barrier filters". That is, their filtering media acts as a physical barrier to dust particles, and once a dust particle covers a pore in the media, air can no longer flow through that space. This principle is called "surface loading". K&N air filters are built using a fabric filtering material which absorbs dirt and dust particles instead of physically blocking them. This is a principle called "depth loading". The pores in the material continue to let air flow through as the filter absorbs dirt in the media.

From here https://www.knfilters.com/faq.htm#5

 

Adding a K&N filter only makes your car SOUND like its going faster. You know, like adding a fart cannon to you car.

 

You're right that without a 3rd party test, all that we hear about OEM vs aftermarket is all speculation.

If your source is from K&N, then it's not a valid nonbiased response.

But to your point, we don't know if OEM does filter more crap out.

To me, it's just logical that a filter that keeps more out has less airflow that can go through it.

Yes, perhaps design can achieve both, but I just don't see how that would work. But I may very well be wrong, but for me, when in doubt, i'll stick with OEM where a bunch of allegedly smart Germans worked on the design of parts/vehicle.

 

Right, I can only go by my experience and I've used these filters my whole life not one blown up engine. Does it actually seem faster? Yes, it does, not by a lot, but noticeable. The first thing I noticed was the quicker revs. Is there more sucking noises coming from the engine bay, Yes, there is. Have I ever had a problem with my current setup or with any K&N product across 4 different cars, nope.

 

These posts are an interesting read. :- https://mbworld.org/forums/c-class-w...e-you-had.html

 

I was originally going to stay out of this thread and let the OP do his own research through the search feature, but since this thread keeps getting bumped...yes I do have a K&N filter. I also have it on my wife's car (Lexus CT-200h....basically a Prius) as well as the cars I previously replaced. My last daily driver went as far as 185k miles before selling it off to a private party that continued to use the filter I put in.

I understand everyone has their concerns, but over the years I've come to the conclusion that only the OP can decide for his/herself so I don't bother to argue either way (aka...do whatever makes you feel confortable). As for myself, I've been on K&N filters for the past 15 years and will continue to use them on the 1st scheduled filter replacement on every car moving forward, not for performance reasons (since I beleive there isn't any) but for convenience.

The biggest mistake one can make is to degrease then overoil the filter, so now I don't bother. I simply take the filter out of the housing during the service schedule, and drop the filter on a flat surface (dirty side down) to shake any dirt or bugs loose, rotate it 180 degrees (if the drop in filter is symetrical) then put it back in. With a drop in filter, you can hypothetically go through entire ownership cycle of the car without ever having to replace (OR reoil) the filter media.


P.S.
In case anyone is wondering, I do plan to take this W204 to at least the 1st high mileage award (155k miles) before replacing it and this C350 was factory ordered so I've been the only owner. Like in my previous posts I've mentioned, I intend to report my ownership experience (good or bad), and so far I've accumulated 78k miles, so I'm at least half way there. If I have any concerns with K&N or that style of filtration media, I'll gladly report it, but so far it's all quiet on my front.

 

Following on from edgalang's post , I have never had a K & N filter but maybe something similar.

I had a 1979 Peugeot 504 for nearly 30 years & it had done 450,000 km. The head had never been removed & no major mechanical work had been done except for a clutch replacement which necessitated the engine removal which I did myself.

This engine had a half inch thick cylindrical foam air filter of about 5 inches diam & 7 inches in length. I washed out & oiled this filter methodically for the 30 years . The engine was still running smoothly without using oil when it was sold .

My current 1980 Peugeot 504 has the same filter & is still running well after 37 years & has also never had the head removed.

So my point is , if a foam filter is serviced diligently it will give reliable service.

The one proviso I see is that if too much oil is applied it may carry over to the sensitive air flow monitoring equipment in modern engines & cause problems.