HenryPcar

Normally I change my air filter every 20K miles and use the dry stock version. However, a friend uses the oiled version and highly recommend it. I notice on my 997.2, the air filter is quite a ways directing air flow towards the intake and reasoning that there is less chance of oil contaminating the air mass sensor. Anybody here uses the oiled filter and happy with it ?

Highpox1

I have a 997.2 also, and early last year switched to BMC filters. I can't prove I gained any mileage, but I did not lose any performance either (MAF was fine). In December, after 8000 miles, I pulled the filters and cleaned them, then re-oiled using the spray (rather than the squeeze bottle). I let the filters dry, banged off any loose oil, touched up a few dry spots, then let them dry again (for an hour or so). Reinstalled. I had also pulled the MAF and took a look at the wires- all good. No deposits. I spray cleaned it for grins, reinstalled. But... I have not seen the MAF yet after I oiled the filters (the initial filters had the BMC factory oiled job). So far this year I have not had any issues, so I am assuming the MAF is not affected. I know a lot of people use K&N or BMC in Porsches, and I haven't heard they are oiling up the MAF sensor. Reusing oil filters seems like a good way to save some money and gain a little more air flow. I have been happy with mine, and plan on re-using them for as long as they last.

Petza914

Using oiled versions of the flat replacement filters in the factory airbox isn't a great idea because it's very difficult to get the excess oil out of the filter and that could and probably will contaminate the MAF. With the cone style filters used with CAI systems, you can stiff the filter with a lot of paper towels and wrap around the outside them let it sit overnight, and that will absorb any excess oil not well trapped by the gauze filter media. The stock filter in the stock airbox flows fine and may trap dirt better than the oiled version if the latter isn't properly maintained.

None of my cars have stock airboxes and I run oiled K&Ns in them using the reoiling and paper towel method explained above and have never replaced a MAF in any of my cars. Used Oil Analysis also does not show elevated Silicon levels so the filtering is working just fine too. I do have a hydrophobic pre-filter over all of them though which prevents the filter media from getting saturated with water and compromising the filtering effectiveness.

Gofishracing

Use dry OEM

cyclrder

agreed.

doclouie

Monster231

If oiled properly, the oiled filters flow more air (based on a bunch of independent tests, you can google). I don't know if it add HP, but the car definitely feels, acts, and sounds different. The problem is most (me) don't clean/oil them properly. All my problems were related to over-oiling and then jamming the filter into the airbox. Since I adjusted to the correct amount of oil and let it sit for several hours, even overnight, I've had zero issues. I had to replace the MAF on two different cars due to oil contamination

mujeriega

I had the same dilemma around OEM paper filters vs. BMC or K&N oiled filters with oil potentially messing up the MAF sensor. As a result, I found this option from AFE which allows for greater flow, doesn't use oil and is reusable so I can clean it more frequently.
https://afepower.com/afe-power-11-10...y-s-air-filter

I've been using this for the past month and am happy with how the car felt immediately after installing.

In regards to fine dust in the air box, I saw this even with a disposable oem filter after 1 yr so it's not like nothing gets through. The more frequently you can clean your air filter or use a new one, the better they will work. I would rather have a higher flowing filter that I clean every 6-12 months than a lower flowing paper filter that I replace every 2-4 yrs.

okbarnett

I like BMC the best