An internal combustion engine is a type of internal combustion engine that uses a fuel explosion caused by a spark, a gas to expand thereby pushing a piston. In the case of engines Nitromethane an incandescent igniter to put the spark plug when it started it is necessary. Depending on the compression and displacement, you need one or the other percentage, recommending 1/10 car engines use 16% nitromethane, and 1/8 fuel for cars with 25% of nitromethane.