My wife and I just purchased a 2012 Buick Enclave with a 3.6l DI engine. I'm getting ready to change out the factory oil after break-in and am trying to decide which oil to use. I've always been a Mobil 1 guy but I noticed the other day that my local Wal-Mart is carrying Royal Purple in addition to Mobil 1. Both the M1 EP and the RP API meet the Dexos 1 requirements that my owners manual specifies. Anyone have any thoughts / experience / recommendations with these oils in a similar application?