1. Your dealership wrench-man is an idiot. Engine compression has nothing to do with the oil pressure the said engine runs. Also, there are no external "oil pressure lines" on the 2.5L engine; and per the Mazda 3 FSM, oil pressures in the 2.5L run no higher than ~ 62psi @ 4500RPM. There's nothing unusual here - recommend finding a competent mechanic, or learn how to do these basic service jobs yourself.I like K&N oil filters. But the Mazda dealership wrench-man said the high-compression Mazda-3 (2.5L) has high pressure oil lines. So I should stick with the Mazda oil filter. Comments ?