Wow, quite the responses! It's an 05 Mazda 6. Not aggressive, though I'll let it breath a bit more than my wife. Should mention that I do most of my shopping at advance auto, since that's close to me. I think that makes the fram tg the best choice. I've always changed filters at every oci, don't know if that's overkill? The Mazda I usually go with whatever synthetic is on sale (ducking). BMW I drive more aggressively and had used syntec or m1 until they lost the ll-01 rating; next change is Pennzoil.