13% or better NOACK volatility (GF-4 is 15%).
90% or lower viscosity increase in sequence IIIG (GF-4 is 150%).
Piston deposit rating 5.5 or better (scale of 1 to 10, higher is better, GF-4 is 3.5).
These are the pieces of data I have on hand. I don't feel like paying the $30 for the full details of it.