stay away from penzoil and Qstate and any brand oil using wax based crap it will clog any oil passage way have seen a few that came into the engine machine shop that were toast after one race that had penzoil in it when it cooled down the wax covered all oil passage ways causing starvation. rocksurfer is pretty damn close with his advise I have over 12 years as an ASE cert. tech and have played around with different oils and additives