Nitromethane is a nitrated hydrocarbon with the formula CH3NO2. It is a liquid at room temperature.
A major use of nitromethane is a fuel for drag racing automobiles. Proper use of nitromethane can effectively double the horsepower delivered by an Otto Cycle internal combustion engine. This is achieved even though nitromethane has a heating value four times less than standard gasoline. However, since nitromethane has an extremely low stoichiometric fuel air ratio of 2.5:1, a lot of nitromethane can be pumped into the engine per unit air (air is the limiting factor of fuel flow). For comparison, gasoline has a stoichiometic fuel air ratio of 14.7:1. So while nitromethane can only deliver one-fourth the heat per unit mass, 6 times more nitromethane can be used per engine cycle. This results in a 50% power increase, which can be raised to as high as 100% by running very fuel rich.
The disadvantages of nitromethane are its low octane rating, horrible fuel economy, and dangerous nitric acid emissions. It is also very expensive.