Is Kerosene Jet Fuel? How Jet Fuel and Kerosene Really Differ

Yes, jet fuel is kerosene, but not all kerosene is jet fuel. Jet A and Jet A-1, the fuels in almost every airliner, are kerosene refined and tested to an aviation specification: ASTM D1655 in the US, and DEF STAN 91-091 or ASTM D1655 for Jet A-1 elsewhere.

The kerosene in a space-heater jug is made to a different standard, ASTM D3699, written for burners and wick lamps. It has the same minimum flash point, but it is never tested for the properties that matter in flight, such as thermal stability and energy content.

So the real difference is not the chemistry. It is the rulebook each fuel is made and tested to, and only one of those rulebooks gets a fuel into an aircraft tank.

What Is Kerosene?

Kerosene is a middle cut of crude oil. It boils between about 347°F and 617°F (175°C to 325°C), heavier than gasoline and lighter than diesel, and its molecules mostly carry 9 to 16 carbon atoms.

Canadian geologist Abraham Gesner said he gave a public demonstration of his lamp fuel in 1846. He patented the process in 1854 and trademarked the name “kerosene,” taken from the Greek word for wax.

For a century it was mainly a lighting and heating fuel. The British still call it paraffin, while in German the word Kerosin now means jet fuel, the fuel of jets, turboprops and helicopters.

That German usage reflects what kerosene is for today. In 2025, US refineries turned 11.0% of their output into kerosene-type jet fuel and just 0.1% into ordinary kerosene, according to the Energy Information Administration.

In other words, almost all the kerosene a US refinery makes now goes into aircraft.

What Turns Kerosene Into Jet Fuel?

Straight-run kerosene from low-sulfur crude can meet every jet fuel requirement as it leaves the distillation column. In practice, refiners usually treat it first, by Merox treating, clay treating or hydrotreating, and then certify each batch against the jet fuel specification.

That specification controls things a lamp never cares about. These are the ones that matter most.

It must not freeze at cruise altitude

Fuel cold-soaks in the wings on a long flight. Jet A must have a freezing point no higher than -40°F (-40°C), and Jet A-1 no higher than -53°F (-47°C).

Chevron’s fuel review notes that the lower limit makes Jet A-1 better suited to long international flights, especially polar routes in winter.

It has to survive being used as a coolant

Jet fuel does a second job before it burns. It carries heat away from the engine oil, the hydraulic fluid and the air conditioning equipment.

Hot, unstable fuel forms gums and particles that clog filters and foul fuel nozzles. That is why the jet fuel specification includes a thermal stability test on the Jet Fuel Thermal Oxidation Tester (JFTOT, ASTM D3241), a test the heater kerosene standard does not include.

It lubricates the fuel pumps and carries guaranteed energy

Jet engines rely on the fuel itself to lubricate moving parts in their fuel pumps and flow control units, so lubricity matters. The specification also sets a minimum net energy content of 42.8 MJ/kg, which the airplane’s range calculations depend on.

Only approved additives, and often none at all

Every jet fuel specification lists the only additives allowed in it. International Jet A-1 must carry a static dissipator additive and may carry an antioxidant.

The Types of Jet Fuel

“Jet fuel” is a family of kerosene grades rather than one product. Our guide to the types of airplane fuel covers the full range, including avgas; these are the turbine grades.

Jet A and Jet A-1 are the airline fuels. Jet A has been used in the United States since the 1950s and is rarely found outside it; Jet A-1 is the standard almost everywhere else.

JP-8 is the US Air Force fuel. Chevron describes it and Jet A-1 as very similar fuels, with the military additive package (icing inhibitor, corrosion inhibitor and lubricity improver, static dissipator) as the main difference.

JP-5 has a much higher flash point, 140°F (60°C), for safer handling on aircraft carriers. The Navy has used it at sea since the early 1950s.

Jet B and the old JP-4 are “wide-cut” fuels that blend gasoline-range and kerosene-range hydrocarbons. JP-4 was the Air Force’s fuel from 1951 until the switch to kerosene-type JP-8 was completed in the 1990s.

The Air Force moved away from wide-cut for three reasons: it evaporated at altitude, it was a greater fire risk on the ground, and crashes of aircraft fueled with it were less survivable. Jet B survives only where extreme cold makes its low freezing point worth the trade.

Newer fuels are joining the family too. Synthetic paraffinic kerosene can be blended with conventional jet fuel at up to 50% under ASTM D7566.

Can You Put Heater Kerosene in a Jet?

No. Every aircraft engine is approved for a named list of fuels, and store-bought heater kerosene is not on those lists.

Nobody has tested a jug of 1-K for thermal stability or guaranteed energy content. It also has not traveled through the aviation supply chain, which has its own quality and cleanliness controls from the refinery to the aircraft.

The chemistry may be close. The paperwork, which is the whole point of the specification, is missing.

Why Do Planes Use Kerosene Instead of Gasoline?

It started as a wartime shortcut. Jet engines first flew in Germany in 1939 and in Britain in 1941, and the first turbine engines ran on lamp kerosene, chosen largely because the war effort needed every drop of gasoline.

When the commercial jet industry took shape in the 1950s, it chose kerosene-type fuel on its merits. Three advantages kept it there.

More energy per gallon. Kerosene-type jet fuel typically weighs 6.76 pounds per US gallon against 5.97 for avgas. That density gives it about 125,800 BTU per gallon against 112,500, roughly 12% more energy in the same tank.

Turbines do not need octane. A jet engine sprays fuel into a flame that burns continuously, so it can run on a wide range of fuels and has no knock to prevent. That frees it to use a less volatile fuel with a higher flash point.

Lower volatility is safer. A 100°F (38°C) flash point means kerosene gives off little flammable vapor at normal temperatures, unlike gasoline, and loses less to evaporation at altitude.

Piston airplanes are the exception, because their engines do need high octane. That is the job of avgas, and our comparison of kerosene vs avgas covers why a Boeing 737 and most Cessna 172s fill up from different trucks.

Why Don’t Cars Run on Kerosene?

A gasoline car engine ignites its fuel with a spark, after squeezing the mixture hard. That needs a fuel that vaporizes easily and resists knocking, and kerosene fails on both counts: it has a very low octane rating and evaporates poorly at room temperature.

Farmers once worked around this with tractor vaporising oil. The Ferguson TE20 tractor started on gasoline, switched to the kerosene-based fuel once hot, and had its compression ratio cut from 5.77:1 to 4.5:1 to cope with the low octane.

Jet Fuel vs Kerosene vs Diesel

Diesel is the next cut down the barrel. Its molecules carry roughly 9 to 25 carbon atoms, and European EN 590 diesel weighs 0.820 to 0.845 kg per liter, heavier than kerosene-type jet fuel.

Diesel engines ignite fuel by compression rather than a spark, and Jet A-1 has ignition characteristics similar to diesel. That makes it suitable for certain diesel engines, though not all of them.

Aviation has put this to work. The Austro AE300, a 168 hp compression-ignition piston engine used on the Diamond DA42 Twin Star and on versions of the DA40, is approved for Jet A-1, Jet A, TS-1, JP-8 and other jet fuels.

With a service bulletin completed on specified engines, the same engine family is also approved for European EN 590 road diesel.

These engines are why airport jet fuel now shows up in small training airplanes. Our guide to diesel aircraft engines explains how they work and why they have not replaced avgas engines.