Im looking for some 3.7L(5-20w on the cap) data on the 2009 Mazda 6 or maybe the CX-7/9. The owner's manual states pretty much use anything oily from 5/10 20s-40s. I know its impossible to pick an oil for best protection w/o testing but I if one didn't care about mileage what would an oilguy pick? Currently running M1 5-20w and looking at PP 5-40w maybe. We can also use this post to compile 3.7L data.