I use the purolator pl14610 at times (instead of the pl14612), which is basically the same as the subaru version but longer like that mazda one, haven't had any issues. However with the longer filter, it will be the lowest point on the car (aside from maybe the downpipe). So if you offroad it may not be the best idea (and might not clear some skidplates).
Turns out the PL14610 IS the filter spec'ed by purolator for the 09+ RX8, so there should be no issue using the mazda version! (its also listed for a lot of mazda/ford/infiniti/nissan/dsm/honda/acura etc cars). Looks like this tokyo roki mazda filter will be perfect as it does have the higher bypass pressure (the purolators have pretty high bypass pressure compared to most other aftermarket ones, but not quite as high as the subaru/mazda oem ones)
Just a note, its only the 09+ that have the bigger can and higher relief pressure, the pre09 filters are the same as the aftermarket subaru ones (ie 11-18psi, and short)
04xt/4eat, 16g, STI bits and bobs
Last edited by funkymonkey1002; 10-25-2010 at 09:41 AM.