Originally Posted By: kschachn
Warmed to? What does that mean? Do you have technical or specific objections or just prefer to live 30 years behind the times?
I never can understand the fascination with straight weight oils compared to modern multi-viscosity ones. What benefits do you perceive for a straight weight? I can only think of negatives.
To make a multi viscosity oil, the higher the viscosity, ie 5W50, needs more viscosity improvers than 10W30, the improvers negatively affect lubrication and can sheer down. Straight weight oil has no viscosity additive, more oil less additives.
In a very extreme circumstance when you look inside a 2 stroke Detroit that was run with 15W40 vs. SAE40, will have oil in the intake and exhaust ports with 15W40, cleaner with SAE40. I'm seeing better oil control with straight weight oils.
The only benefit I see to multi viscosity oils is cold starting.