K&N filters
 

Anyone have a K&N filter in their A6? Does it make any difference at all as far as perforamnce or gas mileage is concerned. K&N works great on some cars but not others, just wondering what are other's experience has been with K&N and A6.

Thanks

I had one, removed it for now, but planning to reuse it. Well here is the reason.

Our cars use hot wire Mass Air Flow (MAF) sensors for metering intake air. If an over oiled K&N filter is used, then the oil can coat the sensor wire and MAY interfere with the sensor operation. Other cars use Manifold Absolute Pressure (MAP) sensors and these are closed sensor which do not get affected by the oil.

Also the other thing is that K&N filter technically passes more dirt than the factory filter. Yeah, some say the amount of dirt that is getting through is negligible, but for maticulous (aka anal) person like me, any amount of dirt is not good.

So why am I thinking about reusing the filter? Well, the truth is that K&N filter does let more air in. (In addition to more dirt) I am getting my car chipped and more air would be a good thing in a performance application.

FYI, when I had the filter in for a few thousands of miles, I did not notice any gain in performance or mileage figure.

I've used one for about 40k miles with no problems. You just have to drain off the excess oil real well, so it does not mess up the MAF as stated above. Performance - no noticeable change. Gas mileage - maybe very slight improvement. Savings - this filter should last a long, long time. Plus I have them in my Crossfire and motorcycle so I spread the cost of the cleaning kit.

Stick with OEM, K&N creates too many issues with dirt and oil with only nominal, if any, improvements.

When I use K&N, I never re-oil the filter, I just buy new once every 2 years. k&N usually does nothing for cars that breath well to start with. I guess the A6 is one of those cars.

I've been running a pipercross. Foam was very porous, a little worried about particulate penetration, and now paranoid about the MAF.

How does the foam filter perform, any improvemnt as far as performance or gas mileage?