I have a 2011 Silverado 5.3 that I have been using PP in since I drained the factory fill. There is no mention of dexos in my manual or oil cap(I bought it in 2010). So I called the warranty center (for the factory warranty) and they told me I dont have to use dexos if it wasnt printed in my manual and to use whatever the manual said (gm 6094 I think?). Dealership confirmed this, and the service manager also said that if the oil exceeds dexos standards, even if it isnt licensed there is no way they could hold that against you in court should your engine have an oil related failure. If I still had to use dexos Im pretty sure I wouldnt want that hassle, but since Im off the hook as far as this dexos "requirement" goes, Im upgrading to Pennzoil Ultra. Hope this helps anyone who might have a 2011 GM with the old requirements in the manual.