Part of the Fuel-Powered RC Airplanes Center
I treat fuel as part of the engine setup, not as a generic supply that happens to make it run. The fuel affects cooling, lubrication, starting, and reliability, and a blend that works in somebody else’s engine is not automatically right for yours. I start with the engine manufacturer’s specified fuel type, oil content, and break-in instructions, then handle and store it so the mixture stays clean and clearly identified.
This guide is part of the Fuel-Powered RC Airplanes Center.
Glow Fuel
Glow fuel commonly contains methanol, lubricating oil, and nitromethane in proportions selected for the engine. Oil type and percentage matter because the fuel supplies the engine’s lubrication. Do not reduce oil content based on another pilot’s recommendation unless the engine manufacturer allows it.
Methanol absorbs moisture, so keep the container sealed and avoid repeatedly leaving it open at the field. Use a clean pump and fuel line, and do not pour questionable fuel from an airplane tank back into the main container.
Gasoline and Oil
Gasoline RC engines normally require gasoline mixed with a specific two-stroke oil at a manufacturer-approved ratio. Ratios are expressed as gasoline-to-oil, such as 40:1 or 50:1. The correct ratio may differ during break-in, so read the instructions for the exact engine and oil.
Measure the fuel and oil accurately. The RC Plane Lab gas/oil calculator can do the arithmetic, but the engine manufacturer still determines the correct ratio.
Mixing Without Guesswork
- Use a clean, approved fuel container with enough empty space for mixing.
- Measure the gasoline volume and the oil separately with suitable equipment.
- Add the oil according to the specified ratio.
- Seal the container and mix it thoroughly.
- Label the container with fuel type, oil brand and type, ratio, and mixing date.
Never rely on container color or memory when several fuels are in the shop. A clear label prevents glow fuel, gasoline mixes, smoke fluid, and straight gasoline from being confused.
Storage and Transport
Store fuel in approved, tightly closed containers away from ignition sources, direct sunlight, children, pets, and living spaces. Follow the container, fuel, oil, local fire-code, and transportation requirements that apply where you live. Do not store a leaking or swollen container “until later.”
Transport fuel upright and secured so it cannot tip, leak, or move around the vehicle. Avoid leaving it in a hot vehicle longer than necessary. Carry only what is appropriate for the flying session and field rules.
When Fuel Is Questionable
Do not use fuel that is contaminated, separated unexpectedly, full of debris, stored in a damaged container, or impossible to identify confidently. If an engine that was reliable suddenly becomes difficult to tune, fuel condition is one of the items worth checking before changing every needle setting.