Fueling Your Nitro RC Car

Nitro RC cars run on a blended fuel easily available at local hobby shops or online.  It is made up of a blend of methyl alcohol (methanol), nitro-methane (nitro), and oil. In order to understand how nitro fuel work, you need to know what each of these three components does for the car.

Methanol provides the main power to the engine and is the main ingredient in model fuel.  It has an ignition point that allows it to be ignited with the kinds of platinum-element glow plugs used in RC engines, and it releases more energy per pound of air than gasoline. Because it’s easy to get, it’s not expensive—you’ll find model fuel much more reasonably priced than regular gas.

Nitro-methane is added to assist the idle and acceleration and to enhance power output. Nitro is referred to as a “hot fuel,” and is only used in small amounts in model fuels.  It can be explosive if not handled correctly, so take care to read the fuel tips offered here, and always follow the manufacturer’s instructions when filling up your RC.

Oil is need as a source of lubricant for all the moving parts in the engine. Here 2-stroke and 4-stroke engines will require different fuels, since 2-stroke engines have no separate oil reservoir, and need oil mixed in with their fuel.  There are two types of oil found in model fuels- castor oil and synthetic oil.  These can be used by themselves or in a blend, with synthetics being far more common these days.  This is mainly because synthetics are cheaper and less gummy than castor oil, which used to be the only used.  For some engines, a blend with a large percentage of castor oil may work best, since it is actually a better lubricant at higher temperatures.  The synthetics are far less messy, however, and leave less gum on your engine.  You’ll be able to choose from blends of synthetic and castor oil that vary in their percentages- try out a few to find one that runs your engine best.

Fuel blends are expressed in percentages based on the amount of each component ingredient used, and of course the one right for you will depend greatly on your car and engine.  Most model fuels contain mainly methanol, to which about 20-22% oil and 10-15% nitro is added. Be sure to check your owner’s manual for suggestions and guidelines about which blend is correct.  Bear in mind that you may have to try out a couple of different types and blends before you find the one that’s right for the way your engine is tuned.  And if your engine isn’t running properly, one of the first things you should do is change the fuel.

Taking proper care of your nitro car’s fuel is extremely important.  Not only will it help your car run better and make for less wear on the engine, model fuels are flammable and could be dangerous if not properly stored. 

Nitro fuel should not be stored in unsealed containers. Because methanol mixes easily with water, the container you store it in should be completely air tight.  Otherwise, air could get in and evaporation or condensation could occur, ruining the fuel.  It will cause your engine to run too hot and be quite damaging to your car’s fuel and exhaust systems.

Store your fuel at room temperature, and at a constant temperature.  Again, you want to avoid any air in your container or in the fuel, which temperature swings can cause to condense.  Do not store your model fuel in a room that varies widely from hot to cold or vice versa.

Keep model fuel away from light.  Nitro methane degrades in light, which means you need to store your model fuel in a cool, dark place.  If you leave it exposed to sunlight or store it in a brightly lit place, the nitro will degrade completely, as though it hadn’t even been added to the fuel in the first place.  This will cause your engine to run very poorly, or cause poor starts or stalling.

Do not store fuel more than a year.  The fuel will begin to breakdown and lose potency.

In addition to following all these steps, you must also replace your model fuel frequently.  Though proper storage will keep your fuel fresh and running clean, it cannot be stored for years and years.  Most manufacturers offer some guarantees on their fuel, but these will not apply if you have stored it for an extended period of time.  Most importantly, old fuel can be dangerous, so don’t leave it stored indefinitely.