Nitro engine

A nitro engine generally refers to an engine powered with a fuel that contains some portion (usually between 10% and 40%) of nitromethane mixed with methanol. Nitromethane is a highly combustible substance that is generally only used in very specifically designed engines, and is primarily used almost entirely by itself in certain high-performance classes of automotive drag racing.

The term "nitro" has only come into use in the last few years to describe these engines, and has its origins in marketing hype in the model car market. For the fifty or so years prior to this term since the engines were first developed, they were simply referred to as "glow engines", but the term "nitro" has more impact in ad copy. These engines are actually fueled by methanol, but the fuel is often doped with nitromethane as a performance additive. The ignition system consists of a glow plug - hence the proper term "glow" engine - which has a coil of platinum containing wire alloy, usually platinum-iridium. The glow plug is heated with electric current for starting, after which power is disconnected and the combination of residual heat and catalytic action of the platinum alloy with methanol ignites the fuel mixture.