What kind of fuel does an aircraft use? I think there's 3 types

Hi there,
I was wondering what kind or type of fuel for aircraft use, I think there are 3 types of fuel but I can’t remember for different aircraft. Any help is greatly appreciated. TIA

im not an expert in the matter but im pretty sure spark ignited piston planes use avgas which is basically high octane gasoline and all jets and turboprops use jet A which is based mainly on kerosene.

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And AVgas comes in different grades, containing different percentages of octane. Each grade has a corresponding colour that you’re supposed to check as part of the pre-flight inspection to make sure your aircraft has been fueled with the correct grade. 100LL, for example, is blue.

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A few can run on gasoline. I once talked to an Icon A-5 pilot and he mentioned running his plane on gasoline, but his oil had to be changed sooner if he used it.

Rotax and Jabiru engines usually run best on MoGas which is unleaded gasoline, usually 98 octane.

AvGas is low lead gasoline usually with 100 or 110 octane. That’s the most common and generally used for piston props with i.e. Lycoming or Continental engines.

Jet A (kerosine) is used for jets and turbo props as well as Diesel engines like the Continental CD300 which the Diamond DA50 RG uses.

in my 1985 C152 manual, it actually lists two other types of avgas in addition to 100LL one with pink dye the other with green. Neven in my life have I seen these fuels however in the real world. I brought it up on my final checkride to the DPE and he looked at the manual and told me thats interesting, and he said he had never seen those fuels ever in his life as well. (note: i did not bring it up to him until well after I passed and had my cert in my possession lol).

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IIRC there used to be more grades of leaded avgas in use, with higher or lower octane ratings, but things kinda consolidated and nobody makes the pink or green ones anymore. 100LL, the main avgas with a blue tint, is “low lead” compared to a previous version but still sufficiently leaded for all the engines in the modern GA fleet.

There’s also now an unleaded 100-octane fuel, G100UL, which apparently comes in a yellow color. The transition to unleaded fuels has been slow and will likely continue for some time, as pilots and engine maintainers are understandably very conservative about changing the fuel characteristics!

Note that kerosone-based fuels are not leaded at all – leaded avgas is a small drop in the bucket of the total gasoline variants used for cars and trucks, and most commercial aviation runs on jet fuel. Hence it not being a big hurry to transition the GA fleet, even though lead is an annoyingly poisonous heavy metal and stuff. :wink:

</All my knowledge is theoretical, beware! ;)>

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And Military Jet fuels, currently JP-4 thru JP-8

Yup. I used to be a lineman at a couple airports (and used to fly C-150s and C-152s). We sold both 100LL (blue tint) and 80 avgas (red or pink tint). I believe the 80 octane was better for the lower compression engines that could run it (like the small Cessnas) because it had less lead in it (and that could foul spark plugs).

I assume the refineries just stopped really producing the 80 octane avgas since the market was so small. I last saw it available at FBOs in the 90s, but not sure when it was finally gone.

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