A lot of people are using rotella(synthetic and conventional). That brand still has a good ZDDP additive package(zinc and phosphorous). If you want synthetic(and can afford $8 or $9/qt), Redline is the way to go. Redline has a very high moly content, as well as zinc and phosphorous. Redline is far superior to mobil 1, amsoil, royal purple, etc. in its anti-wear additives. This info is from the virgin oil anaylsis chart on bobistheoilguy.com. I'll be using it next oil change.