I've been using the purolator oil filter for a while now and I'm wondering if its efficiency is really as good as they boast. I know they also make bosch, which is also a good filter. The purolator as I'm sure everybody knows is 97.5% and pureone is 99.9%. Does anybody know the multipass efficiency? I'm wondering why purolator is so cheap compared to all the other brands at the local auto store. Thanks.