Just bc an oil has an A3 rating doesn't mean it's more shear stable then one that doesn't. Mobil 1 0w-40 relies on VII's and has a HT/HS of 3.6, A3 rated. But an oil like Mobil 1 10w-30 or 0w-20 is much more likely to stay in grade then the 0w-40. This has been talked about before. So just because your using an A3 rated oil, doesn't mean everything. Agree, disagree? If the new M1R uses a higher quality base oil, and less SS PAO, they would be able to achieve higher shear stability by relying on the thicker base stock. Does anyone think this is what they are doing with this new oil? I borrowed this from TS awhile back.
quote:[ February 01, 2004, 11:56 AM: Message edited by: buster ]
Mobil 1 uses a relatively inexpensive, 3 or 4 Cst, PAO basestock which is thickened using the high vis. supersyn PAO - the SS takes the place of a conventional VI modifier. This makes for a very shear stable formulation, but does little for wear protection or volatility at high temps.