Well before this I was using the 300V and apparently its the same rating as the royal purple, they both have an SL rating is that the rating that you talikng about. because apparently the way oil is rated is by these letters eg. LG, LJ, LS, LM and apparently LM being the best. Please if some1 knows wat I'm talking bout than tell me if it's right or wrong. Caus this is coming from a performance shop owner not me.