Methanol is the main ingredient. It provides most of the fuel's ability to burn. In order to burn the glow fuel, a glow engine must have a glow plug. The glow plug burns very hot as the engine runs because of a catalytic reaction with the methanol. Since the engines turn very fast, a phenomenon known as thermal inertia helps to keep the plug glowing as the engine runs. A small amount of electricity is used to cause the glow plug to glow as the engine is started. Once the engine is running, the electricity is disconnected. 