A method improving fuel economy by the retention of heat in or heating a liquid cooled, internal combustion engine is provided wherein insulation, a heating member, or both are attached to the engine and used to reduce heat loss from the engine or keep the engine at an operating temperature. The engine is subsequently maintained at the operating temperature or a temperature substantially close thereto for either a period of time determined by a user or for a time period that is longer than time periods obtained by following standard practices.