it has been stated numerous times, the LT series (back when designed), NEEDED 5W30, the CHOICE to go 0w20 was gain the necessary IN-TOWN mileage the GOV was mandating at the time...HOPEFULLY, the works for guys like Kory Willis will help relieve a few tight strings the EPA enforced but never really had the authority to do....
my local dealer claims NO FIX has been issued by GM as of yet...that is BS, i think they are awaiting the oil fill caps...i need to go verify the id sticker on the head and see what date it states.