I've been using Amsoil SS 5W30 in my 2012 Buick Regal GS (Turbo and DI). Most GMs spec 5W30, with some newer V8s and non-turbo 4's specing 5W20/0W20.
According to my owners manual:"Use only engine oil licensed to the dexos1 specfication, or equivalent, of the proper SAE viscosity grade. ACDelco...