On my next oil change, I'm going from M-1 0W-40 to GC. I've run the M-1 to 5000 miles. About 1000 miles ago I added 6 oz of the Synpower oil treatment, due to the VOAs on it, and the attraction I have for Moly . I felt that any thickening of the oil by the Synpower would be o-k, as M-1 is on the thin side of a 40 anyways. But now I'm a little torn. GC has produced great UOAs on its own (as has M-1 0W-40). My original plan was to add 6oz Synpower to the GC as well, since it appears that GC lacks Moly. My questions are: Is this a good plan? Is Moly that important? Will the oil be too thick for winter Memphis driving? Car: 1998 SVT Contour HO 2.5L Duratec V-6 138,000 miles 80% highway (apx 50 miles a day) I drive aggresively, tho not harsh.