Oil Guard analysis Sample Date 9.7.06 Mileage 198,787 Miles on Oil 25,700 “ALUMINUM LEVEL HIGHER THAN NORMAL. MODERATE DEGREE OF OXIDATION INDICATED. SUSPECT HIGH OPERATING TEMPERATURE OR OVER EXTENDED OIL DRAIN. DRAIN OIL FROM UNIT IF NOT ALREADY DONE. RESAMPLE AT NEXT SERVICE INTERVAL TO MONITOR..” Viscosity 100C 13.1 H2O 0 Soot 0 Fuel 0 Glycol 0.5 Nit 0 Oxi 19.8 TBN 0 FE 34 CR 0 PB 8 CU 6 SN 0 AL 26 NI 0 MN 0 SI 34 B 0 NA 3 MG 0 CA 0 BA 0 P 0 ZN 0 MO 0 TI 0 K 0 Oxidation and Al flagged. I have a magnet on my fill plug, so FE may be higher than tested (it only had a little debris stuck to it, though). Pennzoil Synchromesh is 9.08 @ 100*C, so it thickened quite a bit due to the oxidation. Car is spec'd for a 75w90 GL4 MT oil - ran Synchromesh for better shifting (it did elimate all grinding I was having with old redline fluid). Refilled with Redline MT-90 (correct spec fluid). I was always worried about the thin synchromesh fluid for protection and it seems like I had a reason to be.