Don't know that there is a test per say for what you are asking. But in response to your question my first thought is oils with a higher FM additive like Moly, etc.; which Pennzoil shows highest amounts of the most readily and easily accessible (i.e. in the stores, Wal Marts, etc.) that you can buy.
quote:Originally posted by Jorton:
Which brands have the lowest friction/resistance at normal operating temp?
That's the $50,000 question. I've seen opinions flying all over about synthetics having less friction, but I have yet to see any hard evidence on the subject.
But common sense and the industry's response to CAFE requirements suggests that lower viscosity oils have less resistance and therefore result in slightly better fuel economy. In simple terms, an XW-20 of any brand will give you better fuel economy than any XW-40.
But that doesn't mean that your engine is designed to run on 20 weight oil, nor does it imply that it will adequately protect the wear surfaces. And as much as I like Moly and ZDDP, they are not being touted as a friction reducers but as antiwear agents.
I'd love to see some tangible data on coefficient of friction vs. oil and additives. The only thing I've seen is how higher film strength improves the resistance of metal-to-metal contact, thus reducing friction & resistance.
purely subjective, but when I check the oil castrol feels pretty slippery . Although my personal choice of dino oils is havoline, pennzoil, and castrol third. Honestly , within the same viscosity, I doubt you would see any noticible difference between major brands.