Engines that use nitro fuel have a glow plug. Similar to a spark plug, the glow plug is so named because a filament inside the plug glows when the plug is hot. An engine with a glow plug is commonly called a glow engine.

Non-electric radio controlled vehicle engines use a methanol-based fuel that contains nitromethane so the term nitro or nitromethanol refers to the fuel, the glow engine that uses nitro fuel, and any radio controlled vehicle that has a nitro engine.

Proper nitro engine break-in is critical for long-lasting performance of your RC. Every new nitro engine should undergo a break-in procedure. Breaking in a nitro engine takes anywhere from one to two hours and about 3-5 tanks of nitro fuel. If you do the nitro engine break-in properly, the up-keep on your RC vehicle is less costly than if the procedure is done hastily and incorrectly.

RC engine size or displacement is measured in cubic centimeters (cc) or cubic inches (ci). In terms of RC engines, displacement is the volume of space a piston travels through during a single stroke. A larger number, whether expressed in cubic centimeters or cubic inches, denotes a larger engine. Displacement is only one factor that determines performance of the aircraft.

Nitro or glow engines use nitro fuel but it's actually a mixture of fuel and air that goes into the engine. The right fuel/air mixture keeps the engine running at its best helping reduce friction and helps the RC engine run cooler. The wrong mixture can cause overheating, excessive wear, or cause the engine to stall. This fuel/air mixing takes place in the carburetor. Oil in the RC fuel Nitro fuel may contain castor oil, synthetic oil, or a mixture of both. When castor oil breaks down at high temperatures it creates a lubricating film -- desirable but somewhat messy. Synthetic oil lubricates well at low temperatures but at high temperatures it burns off and provides little protection. The nitromethane delivers oxygen to the engine, enhancing combustion and delivering more power, and the oil lubricates and helps to keep the engine cool. Even though the methanol is the most plentiful component, it's the percentage of nitromethane that is used to rate the nitro fuel.

The percentage of oil might range anywhere from 8% to 25% with 15%-20% being the typical amount of oil found in nitro fuel. There is some debate as to whether an RC aircraft that often runs at wide open throttle during most of its run needs a higher percentage of oil than an RC car that only runs at full throttle for short spurts.