Originally Posted By: BuickGN
Originally Posted By: CATERHAM
Originally Posted By: BuickGN
Originally Posted By: Ben99GT
I think 10W-30 is usually a more "stable" viscosity in most cases, but when you look at RedLine oils, their 5W-30 doesn't give up any NOACK or HTHS to their 10W-30.
With oils like PP, SynPower, etc. there is a notable advantage for the 10W-30s. Their 10W-30s are less volatile and less shear prone, I'm assuming this is a result of the VIIs.
Agreed. If I could find out if Redline 5w-30 also uses no VIIs, I might try that since there would seem to be no downside.
You could give Dave a call at Red Line and get a quick answer, but I believe RL's 5W-30 uses lighter base oils that their 10W-30 and therefore does contain some VII.
I've run both RL grades and in practice I can't tell any difference between the two grades; they're just too close.
I'm going to have to call him and quit being lazy. I can't run an oil with VIIs because this car is an experiment of running a car for it's entire life span without VIIs and on a heavier than specified oil. I'm very curious to see what the ring lands look like when it gets torn down.
I was mistaken, RL's 5W-30 doesn't contain any VII, their 0W-30 oil does.
To quote Dave at Red Line, "Our 5W20, 5W30 and 10w30 do not contain any VI improver. Our 0W30 does contain a shear stable VI improver. Just some of our very broad viscosity oils require the thickener."
Which begs the question; if you can formulate a 5W-30 without VII's and with the same HTHS and 100C vis but with a higher VI than your 10W-30, doesn't that make your 10W-30 product obsolete?
I think the answer is yes technically but no from a marketing perspective. I suspect the 10W-30 costs less to formulate, therefore your profit margin is higher since you're selling it for the same price as your 5W-30.
Even the best 5W-30 dino's are very shear stable. Conclusion, I think 10W-30 is pretty much an obsolete grade.