Weekend riding through the New England area this entire weekend (RI, MA, CT, NH, VT, and NY) on the 11 HD Trike. There were isolated thunderstorms all weekend long and some cloud bursts were substantial. When the sun was out it was hot and sticky and the oil temperature gauge would read above 240 or 250 when stopped at a light in a small town... then you would ride through one of the cloud bursts and the oil gauge would read around 180. Running through one major down pour (that closed some local roads) the oil temperature gauge went all the way down to 110. So I guess the water cooling method has some merit. By the way... an A+++ on the Harley rain jacket and pants, stayed bone dry the entire trip.