Is airplane fuel different from car fuel?

Jet fuel - formally a kerosene-type aviation fuel made for turbine engines - differs from the gasoline most cars burn, yet in some situations the two liquids are less different than they appear.

Expert behind this article

Jim Goodrich

Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.

Can airplane fuel be used in cars?

Airplane fuel is usable in cars exclusively in diesel engines. Jet-A resembles diesel fuel and runs a typical automotive diesel engine. Avgas is not intended for ordinary car use, yet its high octane rating allows amateur race cars to operate at higher compression ratios, so avgas is occasionally used in amateur auto racing cars.

What happens if you put airplane fuel in a car?

If airplane fuel such as Jet A is put into a car, it floods the piston engine and eventually does not ignite, so the vehicle simply will not run. The kerosene-grade fluid is designed for high-pressure and high-temperature combustion. At ambient under-hood temperatures it refuses to burn, leaving unburnt liquid to stick to pistons and cylinders. Avgas, the high-octane gasoline blended for aircraft, is chemically more accommodating, yet it still brings trouble. Its tetra-ethyl lead instantly ruins the catalytic converter and oxygen sensors, while the extra octane and lead content invite valve wear, piston wear, and chronic overheating in automotive engines. Vapor lock, varnish buildup, and cold-start hesitation are other issues that will be created Thus, either grade of airplane fuel turns a normal car into an unreliable, polluting, and eventually damaged machine.

What is the difference between aviation gasoline and jet fuel?

The difference between aviation gasoline and jet fuel is explained in the table below.

Aviation gasoline, called Avgas, and jet fuel serve different kinds of aircraft engines and therefore carry different physical and chemical signatures. Avgas is a highly refined gasoline formulated for piston engines. It is sold in lower volume to many individual aircraft operators like flying clubs and crop-dusting fleets. To prevent knocking at high altitudes, Avgas contains tetraethyl lead that boosts its octane rating to 100 or more, and it is further treated to be less volatile, perfectly dry, and dyed blue or green for quick visual identification. Jet fuel is a kerosene-based turbine-engine fuel delivered in high volume to airlines and militaries. It is refined to a clear or light-straw color, is unleaded, and carries additives like anti-static chemicals, de-icing agents, anticorrosive agents, and anti-bacterial agents that guarantee stable performance across extreme temperatures and pressures.

Jet fuel's higher density gives it more energy per unit volume, whereas the lighter Avgas offers more energy per unit weight. Jet fuel has a higher flashpoint and a lower freezing point (-40°C for Jet A and -47°C for Jet A-1), making it safer and more suitable for long international or polar flights. Avgas must resist premature ignition at lower pressures, so its higher octane index and lead content protect against knocking while minimizing spark-plug fouling. Although both fuels are strictly aviation products, their formulations are not interchangeable: turbine engines need the cooler-burning, additive-rich kerosene, while piston engines require the high-octane, leaded gasoline.

Is airplane fuel efficiency better than that of a car?

Airplane fuel efficiency is largely better than that of a car. Since 2000 the average plane trip has been more fuel-efficient than the average car trip. The airline industry has outpaced gains in fuel efficiency fourfold compared with car travel over the past forty years, and flying has become 74 percent more efficient per passenger since 1970 while driving gained only 17 percent. In 2012 the FAA energy-intensity gap was 3,193 BTU per passenger-mile for driving versus 2,654 for flying, so energy intensity for airplanes is now significantly lower than for automobiles. Yet these fleet averages conceal occupancy effects: two people in a fairly efficient 30-mpg car generate lower emissions per person than the average plane, and any car that gets more than 44.7 mpg beats the plane. A cross-country airplane trip from New York City to Los Angeles and back emits 0.62 tons of carbon dioxide per passenger, whereas the same trip in the average light-duty vehicle that gets 21.6 mpg emits 1.26 tons. Longer flights generally get better mileage because take-off and climb are the fuel-guzzling segments, and aircraft engines continue to deliver better fuel efficiency, ICAO concludes that the fuel efficiency of new aircraft will increase by 65-80 percent for conventional wing-and-tube designs by 2030. Overall, commercial airliners generally lead in fuel efficiency compared with private jets or single-occupant cars, but for pure fuel efficiency the automobile, on average, is more efficient if both travel at the airline average of 80 percent passenger capacity. If time is not an objective the motor vehicle is the greener choice.

Is airplane fuel cheaper than car fuel?

Jet A fuel is cheaper per litre than petrol for cars because airlines buy fuel in bulk and economies of scale reduce price of Jet A fuel. Jet A averages $4.68 per gallon, while Mogas averages $4.64 per gallon. The small gap widens when taxes are added, because Jet Fuel has lower taxation. Jet A fuel costs less than 100LL because it is used in significantly higher quantities: Jet A produced 576 million barrels annually, whereas 100LL produced 4 million barrels in 2016. 100LL is more expensive because it is sold in low volume and is more expensive to produce. Therefore, Jet A fuel is cheaper than regular gasoline, and even cheaper still for airlines that secure long-term contracts.