Preheating your engine can increase longevity — especially if you’re operating in temperatures below 32?. Metals expand and contract as temperature fluctuates, and each metal does this with varying rates of expansion and contraction. Steel and aluminum have drastically different expansion properties which can affect the clearances in critical parts of the engine. In colder environments, aluminum will contract approximately twice as much as steel. In hotter climates, aluminum will expand twice as much as steel. This is the most critical reason for engine preheating - engine component clearances.
