[Redlinez]

While I get some of the scientific explanations, I don't see how 0W-40 has any advantage over a 5W-40 for track use. I ran the Valvoline 5w-40 old formula for almost 3 years daily and track with no issues whatsoever in 45,000 miles. So if the owner's manual states that 5w-30 Dexos is suitable for daily driving, then how is 5w-40 Dexos NOT suitable to track use? When you look at viscosity charts, the lower flow rate first number is listed for colder climates.