I'm still love'n this 5w-15 Mobil 1 for trucks/SUV's. We've definitely got more get up and go and both of ours ('99's 80 K miles) are running quiter than on the 0w-30 Mobil 1. I think it's got to be engineered differently or something (even though a little voice in my head keeps saying "it's just marketing hype"???)