Other than the fact that the K&Ns are actually in stock at a lot of places and Green Filters seem NOT to be, is there any reason to choose one over the other?

edit: for the C32 obviously.

Thanks,

Bif

I've had the K&Ns for 20K miles, with no problems. There have been some reports of sensor failures from people using K&Ns, but this was probably from over-oiling the filter (which is a potential problem with any oiled filter). I would suggest more frequent oil changes with any hi-po filter, as they generally do not filter the air to the engine as well as stock-style paper filters.

Nothing scientific but I had K&N Filters on my C32 with no problems, and Green Filters on my C55 with no problems, the Green Filters seem to be a preference for many including myself, I will buy them again for my SLK.

Why do you prefer the green filters over the K&N ones? Is it the color?

more efficient design...

I plan on getting some Green filters for my slk55. What are the suggestions for oiling or replacing the filter.

I dont want any problems. Should I just forget about oiling it and simply replace it every so often? Also, how often would you replace it then?

Thanks, Dan

So from everything I have read it seems very few people have gone with the K&N filters over the Green, but no real rationale on why.

For those that have used K&N, have you had any problems, noticed any gains?

For the Green lovers, is their filter design that much different than K&N and if so, what is different? I know 1fastC32 said they are more efficient, can someone explain.

Getting the windows tinted on the new C32 tomorrow and V1 hardwared this weekend. Next will be filters and front flat emblem (where can I get the colored AMG one).

I have had the car a week and it is fun, finally getting comfortable with it. Was up in the Black Hills of South Dakota this weekend, and it would have been nice to have the car there. The hills make for some great driving!

Thanks,
g3.

I have had several cars with K/N filters. They do not filter well unless, they are oiled. People often over oil them. They should be cleaned and re-oiled about every 5k miles. They are fragile, and can be damaged, if not handled carefully.

Without enough oil or by using a damaged K/N filter, one can get a lot dirt bypassing the filter.

I have never used green filters. My C32 has stock filters.

On Cars with MAF (hot wire air flow sensors), like the mustang, excess oil can foul the hot wire on the MAF. I don't think this is a problem with the C32.

you are correct, we have a MAP sensor, not a MAF...

that does make me wonder if it can affect the drive-by-wire system for the throttle body though?

Does anyone know if a C230 SS has MAP or MAF sensors??? I've been curious whether I should get Green filters as well.....

The green filter will only hurt the car, with a MAP sensor (no MAF), if it lets too much dirt into the engine.

The MAF (Mass Air Flow) sensor monitors airflow volume flowing from the air filter to the throttle body. Turbulence on the intake at the front of the MAF
can affect stability of the MAF signal. This really a more accurate way to monitor the engine, but is also more finicky.

On cars other than the C32, such as the C230, look at the intake tract from the air filter to the throttle body plate, the MAF is pretty large and obvious. One can also go to the dealer and ask for the MAF part number. They can show you the drawing and if it does not exist on your model, then you will know the answer.

The MAP (Manifold Absolute Pressure) is a simpler way to monitor the engine, but it is also more forgiving for tuning and does not suffer from air turbulence sensitivity.

Has anyone seen any data to show that Green or K&N filters offer any additional flow, and more importantly, that the C32 or C55 can benefit from that flow? I spent a lot of time learning about the Audi 2.7T engine, and despite everyone's best wishes, nobody was able to increase airflow over the OEM airbox and filter. Even with turbos sucking in air, it was shown that operating with NO FILTER AT ALL did not change a car's performance in real numbers.

The C32 has two sizable filters with lots of area. Before I invested in aftermarket, I would definitely want to see results. Then again, AMG filters are so expensive, the aftermarket stuff may be cheaper!

If you want a filter you will need to go with K&N since Green has nothing out for the 06 C230.