Quaker State 20w50 High Horsepower (semi-synth) ridden for 50 miles in a 2001 Yamaha YZ250F on 10/18/05. Testing done by Blackstone Labs. INSOLUBLES: .2% WATER: 0.0% ANTIFREEZE: 0.0% FUEL: <0.5% FLASHPOINT IN F: 455 SUS VISCOSITY @ 210 F: 81.1 ALUMINUM 46 CHROMIUM 2 IRON 9 COPPER 1 LEAD 271 TIN 1 MOLYBDENUM 58 NICKEL 1 MANGANESE 0 SILVER 1 TITANIUM 0 POTASSIUM 1 BORON 7 SILICON 10 SODIUM 0 CALCIUM 1878 MAGNESIUM 6 PHOSPHORUS 718 ZINC 804 BARIUM 0 this oil seemed to work pretty good with the clutch. no problems what so ever. again the lead is from my race fuel and the alumimum is from the clutch pressure plate. the flash point is one of the highest i've tested and the viscosity ALMOST stayed in grade for the 50 miles it was used. performance wise this is a pretty good oil, but for the cost it can easily be beat by several others.