Interesting to compare the current versions of these two oils.
M1 first
Vis 40: 70.8 vs 73.2
Vis 100: 12.9 vs 12.2
Vis Index: 186 vs 164
HTHS 150: 3.6 vs 3.5
MRV -40: 21,600 vs 20,400
With the MRV so close and M1's high VI and lower Vis 40 it looks like M1 0w40 will be thinner at many start up temperatures.
I wonder where their Viscosity meets.
As we head into the brutal California winter, this could be the difference between our engines surviving or not.
M1 first
Vis 40: 70.8 vs 73.2
Vis 100: 12.9 vs 12.2
Vis Index: 186 vs 164
HTHS 150: 3.6 vs 3.5
MRV -40: 21,600 vs 20,400
With the MRV so close and M1's high VI and lower Vis 40 it looks like M1 0w40 will be thinner at many start up temperatures.
I wonder where their Viscosity meets.
As we head into the brutal California winter, this could be the difference between our engines surviving or not.