familyman
Platinum Member
I've been running the Amsoil HD15w40, and even in bitter cold (single digits) it cranks right up, never any tapping or knocking from lack of initial oil flow. I understand that their 5w30 (?) has one of the best additive packages in the industry, but since I always give my motors a little time to warm up, and tractors run at relatively low rpm, I prefer to run the higher viscosity lube.