Basic Air Filter swap for the E9X M3. I chose the aFe Pro Dry S for both increased flow & filtration. No significant power change expected. I prefer dry filters to oiled ones for simplicity. The car was new to me at ~25,000 miles, and wasn’t sure when, if ever, this had been done.

Requires:

• T25 Torx
• New Air Filter (aFe Pro Dry S) – the model number is different depending on LCI or pre-LCI – the nub holding the filter on is a different length, a very random change

Very simple job here. First pop the hood. The air filter housing is located on the driver’s side.

The housing is held on by a few T25 torx nuts. These nuts don’t need to come out all the way, better that they are undone but still stay on the top portion of the housing. You do not need to take off the 2 10mm nuts to the right of the housing.

With the top off, the filter element is exposed. The easiest way to get it off is to pry it off from the nub side:

Filter out, comparison with old (OEM looks like, probably never changed, and new). There is an angle/shape to the filter, it is not a symmetrical piece, so make sure it goes in the same way:

Install the new filter, and reinstall the top portion of the air filter housing, taking care to make sure all the torx bolts are aligned correctly. May take a few tries.

That’s it! I was tempted to take off the air filter box to rinse it off, but it required a little more finagling than I was willing to do at the time, which is why some images above show the 2x 10mm bolts removed.