Actually there`s no such thing as optimum temp for car engines either It is just a very common myth amongst car-newbees who think they have to constantly check the temp with a tempgun Tune all engines for performance and don`t give a damn about what the tempgun says.
I have had car engines that had to run very hot and lean to run great and others that runs great at much cooler temps. A long time ago I threw my cheap innaccurate tempgun as hard as I could into the ground and have never missed it one bit[sm=idea.gif] When the engine runs great the temp is fine. The engine will tell you if it is to lean or too rich, just whatch it and listen to it. The same goes for all kinds of engines, car, heli, plane, boat.....