My new RT gets 40 with mixed driving. Some of the points Gunderwood makes are valid, but constant temp (water cooling ) hardly made a difference on the GW. A honda civic with twice the engine gets 50% better gas mileage. We really do need to just write it off to a great hobby with old tech. Kinda like small airplanes - that engine technology hasn't changed appreciably since 1945 thanks to our friends in government making certification of new technology cost prohibitive.