NOS or nitrous oxide - a familiar name among drag racers and those who are crazy about speed and power. This gas also called as laughing gas, was once used as an anesthetic for minor surgeries, yet now being widely used in automobiles and other propulsion systems. Many would have seen NOS system in action while racing in the movie- fast and furious. Due to its superb property as an oxidizer, this gas is used in boosting up the performance of bikes and cars. Along with instant acceleration it also increases the horsepower of engines. A nitrous oxide system is one which delivers NOS with right quantity to the engine. Generally air is required to burn the fuel inside the engine.