Does anyone have some hard numbers to back up oil choice on a newer air-cooled Triumph twin?
Triumph spec both a 15W-50 and 10W-40, currently running Amsoil 20W-50 moto. My dealer is adamant that the 50 grade is the only way to go, but since I'm in WI and the cooler circuit has no thermostat I think a 40 would be more appropriate. Summer temps rarely get higher than the mid 80s and I ride down into the teens if the roads are good.
13 Triumph T100 - Delvac 1300 15W-40
03 Chrysler 300M - PYB 5W-30