...I attempted to interpret his reasoning. The following may be relevant to this discussion. I was recently comparing two Synchromesh fluids (not dissimilar from CVT fluid). Pennzoil Synchromesh (VI=208) and Valvoline Synchromesh (VI=157). They have similar KV100, although Pennzoil has slightly lower KV40. Valvoline Synchromesh is a synthetic blend but has lower VI than Pennzoil Synchromesh, which is mineral based. I thereby determined that Pennzoil's high VI was due to a heavy dose of VII, and therefore surmised that Valvoline was superior in this regard.