On my older vehicles (flat tappet) I add in a capful of the OLD GM Engine Oil supplement (EOS) because of the higher protection for wear (high ZDDP count). New oils just don't have the protection. Don't use the new formulated GM oil supplement they have now. You can usually find the older version still laying around. GM p/n 12371532.
I've heard different things about RP, good and bad, but I'm not convinced of it OR Amsoil. I've used mobil 1 in our 02 Camaros and the truck, and no issues ever concerning oil. I think it really has a lot to do with general maintenance approach anyway. If you change your oil at specified intervals, you should be ok.
2010 2SS/RS Auto, Sunroof, Engine Cover. Transformer Edition package.
2013 ZL1 ragtop #5478. 1 of 54 CRT M6 'verts.
Last edited by el ess X; 09-04-2009 at 10:48 AM.