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Comment by tw04 | Hacker News Reader

Priming has nothing to do with cleaning. It’s higher octane fuel. If your car Isn’t designed for higher octane fuel it will run like garbage. The whole point of high octane fuel is that it requires a higher temperature to ignite. If your car Isn’t designed for it it’s most likely only going to partially burn the fuel.

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No, the main point of high octane fuel is to be resistant to higher compression ratios so it doesn’t pre-detonate. Spark plugs have no issues igniting it.

What op is referring to is additives that are added in by some gas dealers to the high octane fuel to upsell you. “Techron” is one I recall seeing at Chevron IIRC.

You can sometimes buy the additives separately. e.g. for Techron: https://amzn.to/33LH1RN

The parent comment is right. It's not just the spark; heat and pressure are also part of what ignites your air/fuel mixture.

Not with gasoline. A gas engine can ignite at temps well below 0F and low compression.

You might be thinking of diesel. Diesel depends on compression to combust and has heater coils to ensure minimum temps as well.

This is more obvious when you read engine specs and they have minimum octane ratings, not specific ratings.

High-octane fuels will not burn poorly. It just isn't necessary to increase octane further once the threshold of knocking/self-ignition at the target compression and cylinder temperature is reached.

Plus you missed the point: In many places the premium fuel is the same octane number as regular (e.g. 95), but premium is with additives for <insert vague marketing>.

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