mobil 1 oil is the best. thats why it come's stock on alot of performance type cars now adays. and plus i work at a mobil so you gotta go mobil not castral lol that castral isn't syntethic it's actually a blend i belive mobil 1 is the only 100% syntethic oil out their. so it's great lol. don't use anything but it if your going syntetcic.