These two products have different Royal Purple prices and part numbers.
Are they fundamentally different? Although i do not have statistical infomaition heresay ahs told me the Racing RP 21 has less detergents than thier OEM 5W30
Another Post brought back from the Past, Yes the 2 oils from RP are formulated entirely diferent. The XPR or "racing" oils have 50% more synerlec additive as well as up to 50% more ZDDP. Plus the TBN's are higher on the XPR which hover around 12-13 vs. 9-10 on the Standard RP.