An external tank heater is an electric heater that heats the engine or transmission of a vehicle to give quicker starts and protect your engine from damage that can occur during cold weather starts. Warmed engines also deliver better fuel economy, plus improves oil flow to provide better lubrication to the engine, which reduces wear and increases engine life. The one-piece molding eliminates the possibility of leaks and the tapered outlet design pushes coolant more effectively than other styles. The die cast aluminum is recyclable.