Select The Correct Fuel
It's very important to use the correct fuel in your TRX engine for maximum performance and engine life. Traxxas Top Fuel should be used to ensure correct engine lubrication, performance, and ease of tuning. it's been proven in thousands of engines, so you can count on it every day for great performance.
Top Fuel is the only fuel which is 100% certified for use in Traxxas land engines. Traxxas Top Fuel is made with just the right balance of the highest grade natural and synthetic lubricants to allow excellent throttle response and the best top-end performance, without sacrificing long-term durability. All of the components in the fuel are carefully selected from the best materials available and then custom blended to match the metallurgy and temperature characteristics of Traxxas engines.
You may use 10%, 20%, or 33% nitro-content fuel. Use the same percentage all the time; don't switch back and forth between 10, 20, or 33% fuel. If you break-in your engine on 20% fuel, then we recommend always using 20% fuel. If you do need to change nitro percentage, you will need to retune your engine.
What about Other Fuels?
Can other brands of fuel be used besides Top Fuel? There are other fuels that can provide satisfactory performance, however there could be long-term costs in the form of decreased engine performance, loss of tuning ease, and shorter engine life. Everyone has an opinion or a claim to make about fuel. The engineering team at Traxxas spent over two years developing the TRX 2.5 Racing Engine. No one knows more about the specific fuel requirements of Traxxas engines than Traxxas engineers. We strongly urge you not to take chances with your engine investment and use the Traxxas fuel made for the TRX 2.5 or TRX 3.3.
Some fuels are capable of destroying your TRX engine!
If you must use a fuel other than those listed, contact TRAXXAS first, at 1-888-TRAXXAS, to find out if the fuel is safe for use with TRX engines.
Handling the Fuel
Follow all directions and warnings on the fuel can. Keep the fuel tightly capped at all times. Some components in the fuel can evaporate very quickly and upset the balance of the fuel. Do not store unused fuel in the fuel-dispensing bottle. Immediately return fresh unused fuel back into the fuel can. Do not mix old and new fuel. Never mix different brands of fuel together. Store the fuel in a cool dry location, away from any source of heat, ignition, or combustion.

Filling the Fuel Tank
Use a fuel dispensing bottle (Traxxas Top Fueler, part #5001) to put fuel into the fuel tank. To fill the fuel bottle, squeeze the air out, insert the dispenser tip into the fuel can, and release your grip on the bottle. As the bottle expands, fuel will be drawn into it. To fill your model, flip up the spring-loaded cap on the fuel tank, insert the tip of the fuel bottle, and squeeze to dispense the fuel. Fill the tank until the fuel level reaches the base of the filler neck. Close the fuel tank lid, making sure it closes tightly.
Fuel Tank Seal Adjustment
The rubber seal on the fuel tank is important to the function of the engine. The fuel tank is pressurized by the exhaust system to provide reliable fuel flow. If the tank lid does not seal properly, an air leak will be created that can cause your engine to run erratically and be difficult to start. If necessary, the rubber O-ring tank seal can be adjusted for improved sealing by tightening the screw on the underside of the tank lid.
CAUTION: ALWAYS FOLLOW THE PRECAUTIONS PRINTED ON THE CONTAINER OF FUEL. KEEP IT AWAY FROM FLAMES AND CHILDREN. THE MIXTURE IS FLAMMABLE AND POISONOUS.