Originally posted by GregS
Another option is Amsoil 10w-40, but hasn't it been determined that 10w-40 has too many additives and that a 15w-x is preferred?
that applied to 10w-40 dino oil many years ago when the viscosity modifiers they used had a tendency to break down. i don't think that problem exists anymore. i put in 15w-40 delo late in the fall and this winter i wished i had used mobil 1 instead...