Originally Posted by rickair7777

High performance piston engines would need TEL or some other octane booster.

Jet engines could plausibly evolve from the turbo chargers used to boost piston engine performance. Add a combustion chamber to a turbo charger (and an afterburner if you want to go all out). In fact early jets bore a resemblance to turbo chargers, so there is likely some basis in fact to that.