Quote:

A 5w-20 synthetic oil might perform more like a 3w-20 when compared to 5w-20 dino oils.




My car specifies 5w-20. Since I put on a lot of miles between changes and it sees a lot of cold starts and short trips I run amsoil synthetic in it. I will tell you that oil is almost as thin as water even when cold! I'm sure they spec it for fuel mileage. The engine was designed with that in mind so I have no problem with it.