Can a gas car engine run on pure octane booster?

This guy experimented on lawnmower engines and concluded they ran very well on octane booster, but can car engines run on pure octane booster?

  • Seems you already have your answer? Commented Sep 8, 2021 at 21:10
  • I wouldn't do it. These products are intended to enhance the octane rating of gasoline not replace it.
    – jwh20
    Commented Sep 8, 2021 at 21:49
  • @jwh20 I suppose I could rephrase my question: "Can a gas car engine run off jet fuel?" Jet fuel has a very high octane rating.
    – Geremia
    Commented Sep 8, 2021 at 22:21
  • @Geremia - That was a 4-stroke engine. Besides, combustion is combustion. And Jet Fuel is very refined kerosene (for the most part). Commented Sep 8, 2021 at 23:37
  • Jet fuel has low octane similar to kerosene . Octane booster is likely ethanol or a mix of alcohols . Another possibility is aromatics like xlyenes( used in avgas). Commented Sep 9, 2021 at 0:25

2 Answers 2


An important part of good quality gasoline is isooctane. It's the "good stuff" in the definition of octane rating with octane number 100 (with the "bad stuff" having octane number 0 being n-heptane). Mixing isooctane into low-quality gas increases its octane rating, so in that sense, it is actually an octane booster.

You can run an engine on pure or slightly impure isooctane. Finding completely pure isooctane is of course expensive, but you can get near enough by purchasing "small engine gasoline" / "alkylate gasoline". It has very clean, non-smelling and non-carcinogenic emissions (because it doesn't have aromatics), burns without carbon residues inside the cylinder and can be stored for about 5 years unlike normal gas which goes stale in few months (because normal gas has olefins whereas alkylate gasoline doesn't). Because it has no ethanol, it doesn't degrade fuel lines as rapidly and doesn't absorb water.

I use alkylate gasoline, i.e. slightly impure isooctane, in all my small engines. I also have some amount of alkylate gasoline stored in case there's fuel shortages and I need it for my car or my electricity generator.


I cheated and looked on the net instead of guessing. Booster is likely either ethanol ( octane 113) , or aromatics xylene ( octane 117 ) , toluene (octane 114). I think these are R+M/2 octanes, but the sites were not specific. Jet fuels are very low octane because they are mostly kerosene with some naphtha . I think it is the naphtha that gives it a little octane. Different jet fuels are different blends so no specific answer. And , you can run an engine on aromatics , some will say it is bad but I don't think so. Pure ethanol may need some engine adjustments to run, like 30 % more fuel through the injectors. Ethanol must have something mixed with it ,(like other alcohols) or it would require a liquer tax (US).

  • 1
    And will the higher concentration kill the seals in the fuel system?
    – Solar Mike
    Commented Sep 9, 2021 at 5:15
  • It did , but now since all gasoline ( US) must contain ethanol the seals ,etc , have been improved. Commented Sep 9, 2021 at 14:30
  • @blacksmith37 "all gasoline ( US) must contain ethanol"? Reference required. So you're saying the gas station where I buy non-ethanol gas for my small engines is lying to me? This includes some Walmarts.
    – Glen Yates
    Commented Feb 8, 2022 at 19:54
  • If it comes from the dispenser pumps it has ethanol. If you are buying a small sealed container like one gallon , it may not be require to contain ethanol. Commented Feb 8, 2022 at 21:40

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