Originally Posted By: A_Harman
I've been wondering what the effect of fuel dilution in motor oil would have on viscosity. So looking up the viscosity of gasoline from various web sources, and using the Widman calculator, I estimate that it would have a viscosity of .48 cSt at 100C, presuming the oil keeps it in a liquid state. (It's a bit past my chemistry knowledge to calculate the viscosity of what is left of gasoline when it is heated to 100C.)
So assuming that the 1.5% fuel dilution is true, and that the gasoline has a viscosity of .48 cSt @100C, and the M1 0w40 has a viscosity of 13.5, a final viscosity of the mixture can be calculated.
(Drum roll, please.)
Widman yields a number of 12.8 cSt with 1.5% fuel dilution in the oil. Since Blackstone got a viscosity of 10.5, there must be some shear occurring.
Keep in mind [censored]'s fuel dilution numbers are regarded as being quite low. The flashpoint was heavily impacted which leads me to believe that there is more fuel in the oil than indicated. I'm sure there was some shear but probably not as much as it appears.