The difference between Nitrous Oxide ("nitrous," "N2O") and Nitromethane ("nitro")

Nitro is made specifically as a fuel for drag racing. It is the result of a chemical reaction between nitric acid and propane. Top Fuel dragsters and Funny Cars use nitromethane.

Us regular folks are more familiar with nitrous. When injected into an engine under pressure, nitrous oxide gives the engine a sudden boost in power by introducing more oxygen into the fuel mixture.

Nitrous oxide is not allowed in any NHRA category except Pro Mod (exhibition) and some E.T. bracket classes