Lots of internet stories going around about Mobil1 being cut back to group 3 oil, not sure how acccurate that is. Since I use Mobil1 0w-40 I was wondering if it is mainly group 4 oil. Given the specs and price , I would think it is still group 4, though I know how things can change quickly in the oil market. I can now find Amsoil and Redline motor oil at similar cost to Mobil1 so if Mobil1 is being cut back I might consider a change. Although everything I've seen on their 0w-40 is pretty impressive.