Quoting Rob P <fristpenny@xxxxxxxxxxx>: > Ok, D^2 you don't like viscosity additives, I can understand that, but > since > the 5 is when cold and the 30 when hot why shouldn't they act the same > in > hot weather? Obviously that is ignoring any problem with the viscosity > additives. Yes, short term they would. > I was told 5w30 was recommended for my 2.2, but the book says no so I'm > > sticking with 10-30, 10-40. I was going to put that 0W30 in my'cuda > that Nowadays, they often recommend oil grades good for fuel economy (and therefore emissions) which may not always be best for long term operation, especially when driven hard. D^2