Editing Nitrous oxide engine (section)

==Mechanism==
When a [[Mole (unit)|mole]] of nitrous oxide decomposes, it releases half a mole of O<sub>2</sub> molecules (oxygen gas), and one mole of N<sub>2</sub> molecules (nitrogen gas). This decomposition allows an oxygen concentration of 36.36% to be reached. Nitrogen gas is non-combustible and does not support combustion. [[Earth's atmosphere|Air]]—which contains only 21% oxygen, the rest being nitrogen and other equally non-combustible and non-combustion-supporting gasses—permits a 12-percent-lower maximum-oxygen level than that of nitrous oxide. This oxygen supports combustion; it combines with fuels such as gasoline, alcohol, [[diesel fuel]], [[propane]], or [[compressed natural gas]] (CNG) to produce [[carbon dioxide]] and water vapor, along with heat, which causes the former two products of combustion to expand and exert pressure on pistons, driving the engine.

Nitrous oxide is stored as a liquid in tanks, but is a gas under atmospheric conditions. When injected as a liquid into an inlet manifold, the vaporization and expansion causes a reduction in air/fuel charge temperature with an associated increase in density, thereby increasing the cylinder's [[volumetric efficiency]].

As the decomposition of N<sub>2</sub>O into oxygen and nitrogen gas is [[exothermic]] and thus contributes to a higher temperature in the combustion engine, the decomposition increases engine efficiency and performance, which is directly related to the difference in temperature between the unburned fuel mixture and the hot combustion gasses produced in the cylinders. 

All systems are based on a single stage kit, but these kits can be used in multiples (called two-, three-, or even four-stage kits). The most advanced systems are controlled by an electronic progressive delivery unit that allows a single kit to perform better than multiple kits can. Most Pro Mod and some Pro Street drag race cars use three stages for additional power, but more and more are switching to pulsed progressive technology. Progressive systems have the advantage of utilizing a larger amount of nitrous (and fuel) to produce even greater power increases as the additional power and torque are gradually introduced (as opposed to being applied to the engine and transmission immediately), reducing the risk of mechanical shock and, consequently, damage.