With the wide range synths that are currently out, there seems to be an assumption that all of them (5w40, 5w50, 0w30+) use VII. We all seem to want to avoid VII as much as possible.
However, I know (at least I've read) that as far back as the early 90's, M1 5w30 had no VII. As technology marches out, is it possible that the viscosity index of the better synths (the real stuff, not the group III pseudosynth), has gotten to the point that they can do say 0w40 without VII. Does anyone have close enough knowledge of commerical oil formulations to have a first hand answer to this.
However, I know (at least I've read) that as far back as the early 90's, M1 5w30 had no VII. As technology marches out, is it possible that the viscosity index of the better synths (the real stuff, not the group III pseudosynth), has gotten to the point that they can do say 0w40 without VII. Does anyone have close enough knowledge of commerical oil formulations to have a first hand answer to this.