Can You Use Aviation Fuel in Cars? – Safety, Compatibility, and Risks

AvResearcher December 06, 2025

 

 
Credited by: Interesting Engineering  

Introduction

Aviation fuel powers airplanes, but a common question among car enthusiasts and DIYers is: can aviation fuel be used in cars? At first glance, aviation fuel and car gasoline might seem similar—they’re both flammable hydrocarbons—but they have very different chemical compositions, properties, and intended uses.

Using the wrong type of fuel in your car can cause engine damage, safety hazards, and expensive repairs. In this guide, we’ll break down the different types of aviation fuel, compare them to gasoline, explore compatibility issues, and explain why using aviation fuel in a car is generally a bad idea.

Types of Aviation Fuel

Aviation fuel comes in two main types:

  1. AVGAS (Aviation Gasoline)

    • Used in piston-engine aircraft (small planes, propeller aircraft).

    • High octane (usually 100LL – “Low Lead”), which improves performance in high-compression engines.

    • Contains tetraethyl lead, which is toxic and not suitable for standard car engines.

  2. Jet Fuel (Jet-A, Jet-A1, JP-8)

    • Used in turbine engines (jets and helicopters).

    • Similar to kerosene; has a higher flash point than gasoline.

    • Not suitable for spark-ignition engines like those in cars.

Key Differences from Gasoline:

  • Octane rating vs. cetane rating: Cars use octane to prevent knocking; jet engines use cetane for combustion efficiency.

  • Additives: Aviation fuels may contain anti-knock agents, antioxidants, and lubricants not designed for car engines.

  • Energy density: AVGAS and Jet fuel are designed for high-altitude, high-performance engines, which differ from car engines.

Why Aviation Fuel Should Not Be Used in Cars

  1. Engine Damage

    • AVGAS contains lead, which can foul spark plugs and damage catalytic converters.

    • Jet fuel has low volatility and burns differently than gasoline, potentially causing incomplete combustion and engine deposits.

  2. Safety Risks

    • Aviation fuel is highly flammable and may ignite more easily under certain conditions.

    • Using the wrong fuel can increase the risk of fire or explosion in a car.

  3. Legal and Environmental Issues

    • AVGAS contains lead, which is illegal for on-road vehicles in many countries.

    • Emissions from burning aviation fuel in cars are toxic and harmful to the environment.

  4. Fuel System Compatibility

    • Modern cars have fuel pumps, injectors, and seals designed for gasoline. Aviation fuel can degrade rubber and plastic components.

Historical Examples of Aviation Fuel in Cars

Some enthusiasts have experimented with AVGAS in cars, often in classic or racing vehicles designed to tolerate leaded fuel. However:

  • These are exceptions, not standard practice.

  • Even in racing, modern regulations restrict AVGAS use because of environmental and health concerns.

  • Jet fuel has virtually no use in cars and would likely damage any internal combustion engine.

Comparing Performance: Aviation Fuel vs Gasoline

  • Octane Ratings: AVGAS 100LL has higher octane than standard 87–93 gasoline. This can theoretically improve engine performance, but modern car engines are already tuned for regular high-octane gasoline.

  • Combustion: AVGAS burns slower, designed for constant high-altitude RPM, not stop-and-go driving.

  • Lubrication: AVGAS contains additives for aircraft engines, not cars, which may harm fuel injectors or seals.

What Happens if You Put Aviation Fuel in a Car

  1. Short-Term Effects:

    • Engine may run temporarily, especially in older engines designed for leaded fuel.

    • Slight performance differences may be noticed, but they are unpredictable.

  2. Long-Term Effects:

    • Lead deposits can damage spark plugs, oxygen sensors, and catalytic converters.

    • Rubber hoses and seals may degrade, causing leaks.

    • Engine knocking or misfires may occur due to improper combustion.

When Aviation Fuel Might Be Used in Cars

In very rare cases, aviation fuel may be used in cars:

  • Classic cars or race cars built for leaded fuels: Some vintage engines were designed for leaded gasoline similar to AVGAS.

  • Emergency situations: Only if no gasoline is available, and even then, it should be diluted and the car inspected immediately after.

Important: For modern vehicles, even small amounts of AVGAS or jet fuel can cause significant damage.

Safer Alternatives

  • High-Octane Gasoline: Modern high-performance cars benefit from premium gasoline (91–93 octane) without risks of lead or engine damage.

  • Racing Fuel: Special unleaded racing fuels are available for cars that require higher octane levels.

  • Ethanol-Blended Gasoline: Often safe for engines and more environmentally friendly than aviation fuel.

Legal Considerations

  • United States: AVGAS cannot legally be sold for on-road vehicles due to lead content.

  • Canada & Europe: Similar restrictions exist; use in cars is illegal and environmentally harmful.

  • Penalties: Using aviation fuel in a car can result in fines, vehicle damage claims, or insurance issues.

Conclusion

While it might be tempting to experiment with aviation fuel in a car, the risks far outweigh any potential benefits. AVGAS and jet fuel are formulated for aircraft engines, not automotive engines. Using them in a car can cause engine damage, safety hazards, and legal issues.

For modern vehicles, high-octane gasoline or unleaded racing fuels are the safest alternatives. Aviation fuel is best left to airplanes, where its properties are carefully engineered for performance and safety.

Remember: Your car and your safety depend on using the right fuel.

AvResearcher

Posted by AvResearcher