Description:As long as the can was yellow, it was the same good oil his paw paw had used with great success 50 or 60 years ago. The code, type, or viscosity meant nothing just as long as the can was yellow. Third, a racer had one of our cams and claimed he used Shell Rotella T oil, but he was showing some lobe tip problems. It appeared to be crumbling away with only runs on it. Under 8X magnification, the tip looked like freshly laid asphalt, tarmac to the English, lots of cavities, not smooth like the rest of the cam. This racer had another engine with our cam with over runs that still looked perfect.