AVGAS 100 is a high-octane, leaded aviation gasoline engineered specifically for spark-ignition, piston-engine aircraft. It is designed to provide exceptional detonation resistance, consistent combustion, and long-term engine protection under high-load and high-altitude operating conditions.
Unlike automotive gasoline, AVGAS 100 is formulated with precise volatility control, uniform composition, and strict impurity limits, making it suitable for aircraft engines that operate across wide temperature and pressure ranges. This grade is commonly used in legacy piston-engine aircraft, military trainer aircraft, and high-performance general aviation platforms that require robust anti-knock properties.
Refining & Manufacturing Process
AVGAS 100 is produced through specialized refinery operations that differ significantly from conventional gasoline production.
1. High-Purity Hydrocarbon Selection: Base components include alkylates, isopentane, select aromatics, and straight-run/reformate fractions. Chosen for high motor octane number (MON), low olefin content, and excellent oxidation stability.
2. Controlled Distillation & Volatility Engineering: Narrow boiling range typically between 30°C and 170°C. Vapor pressure is carefully balanced to prevent vapor lock at altitude and ensure reliable cold-start performance. Volatility profile is more stable than automotive gasoline, especially in thin air conditions.
3. Tetraethyl Lead (TEL) Blending: TEL is added to increase knock resistance and protect exhaust valves and valve seats. AVGAS 100 contains higher lead content than 100LL, providing additional detonation protection for older or higher-compression engines.
4. Final Polishing & Filtration: Multi-stage filtration removes water, sediments, and metallic particles, ensuring fuel clarity and purity required for aviation use.
Key Characteristics (Expanded)
High Octane Rating (100 MON): Designed to withstand extreme cylinder pressures, prevents pre-ignition and detonation, and enables safe operation at high power settings, elevated altitudes, and high ambient temperatures.
Presence of Tetraethyl Lead (TEL): Enhances combustion control, extends engine life in older piston engines and engines without hardened valve seats, and provides lubrication to critical engine components.
Excellent Volatility Control: Ensures smooth throttle response, even fuel-air mixing, and reliable operation during rapid altitude changes.
Clean-Burning & Chemically Stable: Low gum and deposit formation; reduced risk of carburetor fouling and injector blockage; long shelf life when stored properly.
Typical Physical & Chemical Properties
| Property | Typical Value | Operational Importance |
|---|---|---|
| Fuel Type | Aviation Gasoline | Piston-engine compatibility |
| Octane Rating (MON) | 100 | Anti-knock protection |
| Lead Content | High (TEL-leaded) | Engine durability |
| Density @ 15°C | ~0.70 kg/L | Accurate fuel loading |
| Distillation Range | ~30°C – 170°C | Volatility balance |
| Vapor Pressure | Controlled per ASTM | Altitude safety |
| Sulfur Content | Very low | Clean combustion |
| Aromatic Content | Controlled | Material compatibility |
| Color | Green | Grade identification |
| Appearance | Clear & bright | Purity confirmation |
| Net Heat of Combustion | ~43 MJ/kg | Energy efficiency |
Storage, Handling & Safety
Storage Guidelines: Stored in dedicated AVGAS tanks. Tanks must be clean and dry, protected from water ingress, and properly bonded and grounded.
Handling Precautions: Highly flammable due to low flash point. Strict static-electricity control required. Must never be mixed with automotive gasoline or jet fuel.
Applications
Primary Uses: General aviation piston aircraft, military and defense training aircraft, vintage and classic aircraft engines, and high-compression piston engines requiring leaded fuel.
Secondary Uses: Research aircraft and specialized aviation operations in remote areas.
Environmental & Regulatory Considerations
Contains tetraethyl lead, making it subject to environmental regulation. Gradual phase-out in some regions in favor of low-lead or unleaded alternatives. Still approved and necessary for engines not certified for 100LL or unleaded fuels.
Standards & Specifications
AVGAS 100 must comply with: ASTM D910 (Aviation Gasoline Specification), DEF STAN 91-90 (UK aviation gasoline standard), and ICAO Aviation Fuel Quality Requirements. Only fuel meeting all criteria is certified for aviation use.
AVGAS 100 vs AVGAS 100LL
| Parameter | AVGAS 100 | AVGAS 100LL |
|---|---|---|
| Lead Content | Higher | Lower |
| Environmental Impact | Higher | Reduced |
| Engine Compatibility | Older/high-compression engines | Wider fleet |
| Color Code | Green | Blue |
| Market Availability | Limited | Widely available |
Key Advantages
- Superior detonation resistance
- Excellent engine protection
- Proven reliability in legacy aircraft
- Stable under extreme operating conditions
- Designed exclusively for aviation safety