I have no idea how the oil life monitor decides when the oil needs changed, GM says it monitors a lot of parameters but is vague on details... Oil changed last October, (first oil change, 19' Denali) Dealer did the change and I verified the OLM was reset. We didn't use the car much over the winter and when we did it was for relatively short trips so I'm guessing this was a big factor but I still didn't expect 74% of the oil life would be used up in just 2,200mi. I plan to change the oil myself this time so I can be sure it gets full synthetic dexos as I think the dealer uses a bulk blend. Anyone else see shorter than expected intervals for oil changes?... I'm not complaining as I know good quality oil changed frequently will help extend the life of the little turbo DI engine. Oh, 1st oil change was done just shy of 3,000mi.