It involves the injection of Nitrous Oxide (N2O) into a vehicle's engine in-order to increase its power via a chemical compound for a short period of time. This will give the vehicle an increase in acceleration force for a short amount of time.
Players can upgrade a vehicle's nitrous kit with most titles in the Need for Speed series featuring three levels of nitrous injection; dry kits, wet kits and direct port kits.
A nitrous oxide system can be bought for a player's car from a Tuning Shop in some Need for Speed titles. It is available already equipped to vehicles in some other Need for Speed titles such as Need for Speed: Hot Pursuit (2010).
Nitrous Purge is a car specialty that sprays nitrous out of valves found in the hood when activated. It can also be sprayed out of the rims if upgraded. Nitrous Purge can only be activated after being purchased from a Tuning Shop. Players are able to choose the valves' locations, colour, pressure and amount of nitrous that exits from the vehicle whilst activated. This feature is only available in Need for Speed: Underground 2.
- The use of a filled Nitrous bar is more effective than several smaller doses.
- Near missing traffic, slipstreaming other vehicles, travelling in the oncoming lane and drifting will add nitrous bar.
- NOS, Nitrous Express, Edelbrock and ZEX are the nitrous specializing Aftermarket Companies featured in the Need for Speed series.