I use Motul 20W-60 Le Mans 300V full synthetic competition oil. I contacted Motul to enquire about the working range of this oil. They came back to me and said the oil was perfectly happy up to 160ºC, so I have binned the idea of an oil cooler, as being an expensive and unnecessary complication.
There is a Motul oil formulated for air cooled V-Twin engines, Motul 20W-50 7100 4T MA2 Special V-Twin, 100% synthetic. I do like the combined oil temperature and pressure indicator KBMOG, a very neat installation.
