I dunno. Im stickin with Mobil1. When I was growing up my neighbor built engines. Everything from 350 truck engines to Buick 455 racing engines to VTech I4 racing engines. He used Mobil1 in everything including a 280K Acura daily driver and 330K + on his Chevy work truck. But he did tell me not to bother with synthetic when buying a used vehicle or once conventional was used. He also said that 50/50 synthetic/conventional was better than any type of conventional. Polymers help keep conventional oil from breaking down quickly from heat and pressure. Bottom line, they both have polymers in them to protect them against break down, synthetic is just a more pure of a polymer than conventional.