The Flash point is weaker. Not sure if that matters much but for the same price of the previous GF-3 M1, we are getting much less of an oil. Much less additives.
I just noticed the Flash Point of the S2k Amsoil is only 437F, which is mainly a PAO based oil. Seems the higher Ester based oils have higher Flash Points.
Looking around at flash point specs on Mobil 1 data sheets over the years, they seem to be very inconsistent.
Plus just like a 4 ball wear test, I don't hold much faith in what the printed spec tells about an oil in real use.
The only way I'd have much regard for flash point accuracy is if a bunch of oils were tested together and blind. Like the data Terry graced us with a while back.
Noack volatility is a much better predictor of oil consumption in actual service. That's the relevant test parameter to compare if you have a high temp application. I'd ask Mobils tech staff for "Noack Volatility" #s on these new formulations....
The less oil you burn, the fewer deposits you form on the piston skirts,in the ring grooves, in the combustion chambers....