If API = Nothing go buy a SF and stick it in. Good luck with the longevity of ya engine.
I agree that the OE specs are important. Most oil companys will make products to meet the OE Specs. But will the cheaper products still meet these specs after 10,000 or 15,000 kms.
OE specs can be of little relavance, VW spec 506.01 is designed for the new VW Tourag v10 twin turbo diesel with extended oil drain. Now if you dont know what VW 506.01 is designed to do, you buy to stick it into your 600 hp GTR what point is that.
What i am saying is that API specs are a good general guide
ASH