Good luck calling Mobil. I talked with a tech rep last week with the same question and the guy was giving me a range of numbers for NOACK that didn't make much sense. Finally, exasperated, he says, "Well, ya know, that's proprietary information."
Someone on this board posted 13% volatility for M1 0w-30 and 8% for the 10w-30, 2.9 HTHS for the 0w-30 and 3.2 for the 10w-30. Those number sound about right. I'm interested in this spec too since my car is consuming the 0w-30 at three times the rate of the 5w-20 factory-fill dino oil. I'm trying M1 5w-30 next.