This morning when I started my truck (-18F) it turned over extremely hard. I don't see much of a difference between the Amsoil ASL and dino 5w-30 in this aspect. Now, don't get me wrong - this is only an observation that I think some people may find interesting. I really don't expect any motor oil to behave much different. Before anybody mentions it - no I don't want to switch to S2K 0w-30 because of the price and the fact that it hasn't impressed me any more than the ASL in UOA's. I will probably have GC in this time next year, but I doubt at -18F I will notice that much of a difference. BTW, I have a 97 F150 with a 4.6(W). The current oil also has 7,000+ miles on it.