Just for the heck of it I heated the various oils that I have to see what temperature smoke started to appear. Valvoline racing 50W 300 Degrees F Valvoline 20W50 Synthetic 260 Mobile 1 15W50 280 Pennzoil HD 40W 275 Pennzoil 20W50 Dino 300 Delo 15W40 260 Schaeffers 15W40 275 Rotella T 5W40 300 I don’t know if it means anything or not. It was a simple test so I tried it. I used a digital thermocouple meter to measure the temp of the oil. All of the oils seem to smoke really bad at 425 degrees. The winner at that temperature was the Valvoline Racing 50W. This is what I will be using in the V Twin motorcycle because it took the heat and the bottle says that it has friction modifiers and zinc. My motorcycle has a dry clutch. Am I thinking correctly on this?