finalxgohan

hi everyone,
i never have problems replacing my air filters. but lately i came across this K & N filter from this site http://www.overnightautoparts.com/st...ke_code=MB&x=1

I was wondering will it really save me gas and get better performance? or is it just one of those gimmicks?

DynamicS

there are no filters better than the stock airfilter, only because that K&N crap has larger porous holes in the filter media, and that allows more dirt to pass through the filters and into the engine, and thus contaminating your engine oil. Leave that stuff to the ricers.

If you want more airflow through the OEM filters buy a larger airbox from an E55 class car or buy that carbon fiber airbox from renntech, but use paper filters. Forget the oiled foam and cotton, it has it's place on clean racetracks but not on the street. Do a search on the crossfire forum for more specs on which airbox fits the slk320. Unless you have the smaller Kompessor motor, then Im not sure what the next size airbox is available for you? you might have to make a custom CAI.

bazzle

Stick with MB paper.
Even more important with MAF is they are contaminant sensitive.

Standard filter flows enough air to run car over 150mph.

Bazzle

finalxgohan

thx guys. I am placing an order right now. this is off topic for a bit. I am looking for a HID kit. anyone know the right kind for SLK 230?

DynamicS

I know SI has their own kit, and there is also a couple others. On the crossfire forum one guy is installing a set from a late model Lexus. You should be able to burn holes in Supermans' cape

bazzle

H7 plug and play..

Im still not convinced on the K&N

Bazzle

finalxgohan

how many color should I get? there is like from 5000k all the way to 12000k. I looked it up through e-bay and the price is about 88 us dollars.

kenstudios

I dont own the SLK but on my S500 I noticed a realy bad drop in gas milage on city streets. I averaged 11 mpg in the city and around 24 on highway as opposed to the 18 and 26 on oe filters. stay with oe filters.

PhilipM1

That is a very rare case as far as I know. wow!

Educate me, but doesn't K&N make performance filters? I bought one. I love it. I know people who swear by them and wont put anything else in them. Its the first thing they by there cars.

As far as letting more dirt in the engine. I have a K&N in a 1993 190e 2.6. I have about 35K miles on that filter with no cleaning. I get my oil changed and when the oil comes out. Its clean. For having such an old engine, and a filter that "lets more dirt in" why is my engine oil so clean? My valves looks great. No build up from what I can see.

I thought K&N made filters for rally cars when they first came out. Cars that do nothing else but drive through dirt. They suck in dirt all day long. Every day. For some reason I think if a stock filter kept more dirt out. They would use them. I might not know something that someone else does. So please let me know. If you can convince me Ill go to MB and get a stock filter for my car following day. But, I'm pretty sure K&N (and from what Ive heard, GREEN) filters are the best.


Yes, the oil based filter can mess up your MAF. I cant defend that at all.

DynamicS

well if the rally cars used an OEM type filter, they would get clogged up with dirt and loose power, the streets are far less dusty so paper is Ideal. This is the same reason dirt bikes use oiled Foam style instead of a paper or cotton, the dirt and sand will plug both materials, yet it sluffs off the foam filters

DynamicS

most likely your drop in mpg was due to contaminated MAF from the oil and dust from the K&N??

kenstudios

Not the case. Brand new MAF, and when I returned to OE filters my MPG returns to normal. Unless I got bad filters. Is there such thing as a bad filter?

bazzle

Preferably 4300k 5000k MAX or light output drops considerably. Also colors over 5000k are normally illegal on the road in majority of countries.

Bazzle

NA55

Maybe your gas mileage decreased because you got on the throttle more trying feel the power gains of the new K&N filters?...

kenstudios

Haha, I like that.

OK, yesterday I ran with OE filters and I averaged 21 mpg. This morning I just switched to K&N and drove around the block and this was the results.

jerryxu

My slk32 I use high flow filters.
Paper filters are absolute filters. Filter holes has to be smaller than the dirt particles to trap. The drawback is small filter holes result in slower flow. And very small dirt particles usually get through. Advantage is that 95-99% of dirt bigger than the holes will get trapped.

Oiled filters (and fleece filters) are "probability" depth filters. Oil makes the holes "sticky" to all size dirt so bigger holes can be used to trap small particles, which allows higher air flow.

Probability filters are tricky as some percentage of small particles will get through not sticking. The advantage is that it can trap a good percentage of very very small particles. Much smaller than the size of the holes, at say 80-90%. This is something the paper filter has difficulty doing.

At the same total dirt trap level (big and small), a good oil filter can flow 100% more air than the paper filter. They can be designed to flow even more, that is when the total trap level will go down. So much R&D is needed. They get bad names because of some brands of oiled filters just want to increase flow at the cost of lower trap level. K&N should be

Anyway, the design principles are different for the two. I don't know how much HP it gave me. But they work fine on my car for 3 years now.

zoomie

KENSTUDIOS: i can't argue with that. you're making me doubt K&N after having loved them for so long with my rav4.

bazzle

Why dont vehicles companies use K&N type???

Bazzle

Chris A

I have K&N filters in my car and can tell you that there is no increase in horsepower at all. They dont even change the sound. On my other car Toyota Solara I can hear and feel a difference..

I dont see that they are worth the extra cost in the SLK. It appears that these cars have plenty of air flow from stock.

dumokie

I really respect Bazzle and his contributions but, I disagree that K&N is a good filter.
Why don't you just go ahead and dump the filter oil into the intake system thats where its gonna end up anyway.. Hello M.A.F. sensor.
K&N do not filter as well as a paper filter.
I have only used K&N on my dirt track cars, where you had to constantly clean and oil filters due to the mud.
Thats on a carbereted V-8 motor which your abusing anyway. Not a sensitive fuel injected vehicle that your trying to maintain and get max service life and performance out of.
Take a look at WIX filters and do a comparision..
Anyway Bazzle and others in here are great!! I just disagree on this one..

Just my opinion........... Dum,