Best Drop In Air Filter
 

Which do you think is best overall?

Taking into consideration price, lifetime, maintenance, etc.

The Racing Beat is a K&N

Advanced Flow Engineering.......which used to be sold by Racing Beat until they switched over to K&N. I think they switched because the aFE price increased.

IMO, OEM is best, as it probably has the best filtering. K&N may give you better air flow at first, but it doesn't filter as well. Since the performance difference is minimal, and the cost is negligible, I voted OEM.

Of course, I'm biased. I used to run a K&N, but then I read this Miata owner's analysis, this test, and this way less scientific test.

Then some people say that the filtration difference is negligible over life of the car (or how long they plan on keeping it), so they will take all the power they can get.

(And, I own a Mazda Protege, no RX-8 yet...)

the Mazdaspeed filter probably gives the best compromise between filtration capability and airflow... hence the ridiculous price... for a NON-WASHABLE filter!!! :o

Mazdaspeed...

the first link is completely childish and apparently written by someone with little knowledge of the subject

the second infamous link does a good job at keeping variables the same, however they then purposely (it seems) refuse to analyze the secondary filter for how much oil the K&N lost which would effect the amount of "dirt passed".

the third is yet another half ass test performed by bob with no control over variables in the test.

Great timing, lol, as I've been privately asking around too ;)

I'm leaning towards OEM or MazdaSpeed, as I'm not willing to give up filtration for minimal, if any, power gains.

I'm also concerned about the oil from the wet filters messing up the MAF sensors (did I get that right?).

But the MazdaSpeed is bloody expensive. I'm not sure what it's officially supposed to improve. Filtration? Air flow? Longevity?

I highly recommend the Green Performance Filter drop in... you get the benefits of a higher flowing design (like a K&N), but without oily residue coating your MAF every couple months (like the K&N). Great quality, too...