First column is SF and the second is RedLine MTL@9K miles I think I'm gonna go back to RedLine MTL. Should I worry about the high copper? Check out the Iron diff between SF & RL. ALUMINUM 2 / 1 CHROMIUM 1 / 0 IRON 46 / 25 COPPER 40 / 36 LEAD 8 / 12 TIN 0 / 0 MOLYBDENUM 3 / 5 NICKEL 0 / 0 MANGANESE 2 / 1 SILVER 0 / 0 TITANIUM 0 / 0 POTASSIUM 0 / 1 BORON 21 / 32 SILICON 17 / 18 SODIUM 5 / 5 CALCIUM 2949 / 3243 MAGNESIUM 46 / 78 PHOSPHORUS 1445 / 2684 ZINC 1451 / 3386 BARIUM 0 / 4 Blackstone comments: We thought copper may have been a little high last time, though it read at roughly the same level here, so we think it is likely a normal reading for this type of transmission and not a problem. Lead improved and all other wear still read in the normal range. The oil was still in pretty good shape physically. The viscosity was in the light 20W range and no water or excess insoluble material was present. Insolubles would be high for an automatic transmission, but not for a manual. We think this oil still has some life left. Check back in another 8,000 miles to monitor.