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My oil light recently came on in my car. I parked on the side and checked it. There was none on the stick. I added 1 liter and drove about 500m to my garage.

I asked him to do an oil change and to check if the car was leaking oil or if it looked like it was burning it. They found no leak so it look like my car is burning oil.

My question is can a performance air filter (commonly call p-flow) make oil consumption worse? My mechanic suggested it might be the cause to the oil burning.

Note: I would like a general answer. However, I have a 2009 Volkswagen Jetta City.

UPDATE : I can say that after returning to the stock filter, the car has not consumed oil at all (for well over a year - I think 3 oil change since). I might have been because the filter was more restrictive than the stock one as explained in Fred answer's below. But in all cases the consumption stopped when back on a stock filter.

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An air filter that is severely restricting air flow can increase oil use. It is not common. If the air filter is restricted enough a low pressure condition is set up in the intake tube and PCV system. Oil is pulled from the upper valve cover oil/air separator cavities through the PCV fresh air hose into the intake tube. If this is happening there will be liquid oil in the intake tube.

The other way air filters contribute to oil use is cylinder and ring wear. Industry test have shown that a high quality paper filter stops more of the very fine dust that, over time, causes piston ring and cylinder wear which results in oil use and compression loss. The high flow performance filters let more dust past the filter. In this case changing to a different filter will make no difference, the damage is done. Note that this condition can also result in oil entering the intake tube due to piston blowby. High flow filters are appropriate in race engines as they will be rebuilt often enough that the wear due to dust is not a factor. They are not advised in a daily driver.

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To my knowledge there is no way an aftermarket air filter will cause you to burn oil.

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  • This is also my thought but I want some second opinion. Anyway I will remove it for the winter and see if it helps.
    – Rémi
    Commented Oct 3, 2015 at 22:06
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If you have been using this "Hi Performance" air filter for a long time it may have very well caused you car to start burning oil. Some of these filters really don't do much of a job of filtering as their whole purpose is to allow larger air flow into the engine which can only be accomplished with less filtering. You have probably allowed too much grit into your engine wearing out your piston rings. Just my humble opinion. A HP or two is not worth a prematurely demoed engine.

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  • I ran the filter for less than 5k km and I didn't do it for performance. Actually it is generaly less performant tham stock youtu.be/PAIxeQUSg-Q
    – Rémi
    Commented Oct 5, 2015 at 3:11
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    ...which can only be accomplished with less filtering.. - not true. Larger surface area on the filter lets more air in, assuming that the filter was the bottleneck. Big Straw vs Small Straw.
    – 3Dave
    Commented Oct 6, 2015 at 18:52
  • Vancouverites, it's said, don't tan, they rust. @David Lively.....Could very well be true but he doesn't say whether he modified the air filter container to allow an aftermarket type filter........Like a K&N or similar. I am not an expert but would you not have to modify your Air Intake to accept the performance filter? Commented Oct 12, 2015 at 7:12
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    @Rémi.....Wow, thank you. I just learned a great lesson today. I would have never thought that. So I guess the only reason to buy an expensive filter is to buy one that offers better filtering and avoid the performance claims! Commented Oct 12, 2015 at 7:27

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