Glow fuel is a specialty fuel used in model, or glow engines. This fuel is used to power small machines like model planes and helicopters, as well as remote-controlled boats and cars. Glow fuel is a by-product of petroleum distillation, and may also be known as nitro or model fuel.
Standard glow fuel often contains a mix of two petroleum-based products. Methanol makes up the bulk of the fuel, and nitromethane, or nitro, is added for extra power and performance. In some parts of the world, the sale of nitromethane is highly regulated due to this fuel's ability to act as an explosive under certain conditions. In these areas, the nitro is left out and the glow fuel is made entirely of methanol.
These glow fuel components are often suspended in a base material made from castor or synthetic oils. These oils act as a form of lubricant in a model engine. Castor or synthetic oils also help to cool the engine and prevent it from overheating during regular and extended operation.
Each model vehicle manufacturer provides its own recommendations on the best blend of fuel for the company's line of vehicles. Generally, these recommendations differ based on the percentage of nitromethane mixed in with the methanol. For example, a 15 percent glow fuel blend typically contains about 15 percent nitro. The higher the nitro content, the more expensive the fuel and the greater the power and performance of the vehicle in most cases. Most model cars and planes require a 10 to 18 percent glow fuel, though nitro amounts as high as 30 percent may be used under racing conditions.
This specialty fuel can be used in both two- and four-stroke glow engines. Two-stroke model engines provide the easiest operation and lowest maintenance requirements, but tend to consume higher volumes of glow fuel. Four-stroke glow engines require more maintenance, but also offer a higher level of fuel efficiency, which could save on fuel expenses. Very large remote-controlled vehicles may also utilize standard diesel engines, like those used for chain saws, rather than a glow engine.
Glow fuel gets its name from the glow engine used in many model vehicles. These engines contain an internal platinum wire, or filament. When exposed to an electric current, this filament glows white hot, ingiting the fuel in the nearby combustion chamber. In this manner, the filament operates similar to those found in an incandescent lightbulb.