<P> While nitromethane has a much lower energy density (11.2 MJ / kg) than either gasoline (44 MJ / kg) or methanol (22.7 MJ / kg), an engine burning nitromethane can produce up to 2.3 times more power than an engine burning gasoline . This is made possible by the fact that, in addition to fuel, an engine must burn oxygen in order to generate force: 14.7 kg of air (21% oxygen) is required to burn one kilogram of gasoline, compared to only 1.7 kg of air for one kilogram of nitromethane, which, unlike gasoline, already has oxygen in its molecular composition . This means that an engine can burn 8.7 times more nitromethane than gasoline . </P> <P> Nitromethane also has a high latent heat of vaporization, meaning that it will absorb substantial engine heat as it vaporizes, providing an invaluable cooling mechanism . The laminar flame speed and combustion temperature are higher than gasoline at 0.5 m / s and 2400 ° C respectively . Power output can be increased by using very rich air fuel mixtures . This is also something that helps prevent pre-ignition, something that is usually a problem when using nitromethane . </P> <P> Due to the relatively slow burn rate of nitromethane, very rich fuel mixtures are often not fully ignited and some remaining nitromethane can escape from the exhaust pipe and ignite on contact with atmospheric oxygen, burning with a characteristic yellow flame . Additionally, after sufficient fuel has been combusted to consume all available oxygen, nitromethane can combust in the absence of atmospheric oxygen, producing hydrogen, which can often be seen burning from the exhaust pipes at night as a bright white flame . In a typical run the engine can consume between 45 litres (12 US gal) and 86.1 litres (22.75 US gal) of fuel during warmup, burnout, staging, and the 400 m run . </P> <P> Like many other motor sport formulas originating in the United States, NHRA - sanctioned drag racing favors heavy restrictions on engine configuration, sometimes to the detriment of technological development . In some regards, teams are forced to use technologies that may be decades old, resulting in cars that may seem substantially less advanced than the average family car . However, while some basic facets of engine configuration are heavily restricted, other technologies, such as fuel injection, clutch operation, ignition, and car materials and design, are under constant development . </P>

How much fuel does a top fuel dragster use per run