Why is Jet A fuel prefered to Gasoline in aircraft engines?

The compression ratiOS of jet engines are too high to accomodate gasoline

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Two reasons.

The most important is jet fuel is a light oil, which the manufacturers of fuel pumps are well aware of: the fuel pump on a jet engine is lubricated by this fuel. If you run gasoline through a jet engine you will destroy the fuel pump.

The other is gas burns hotter than jet fuel, and will damage the engine.

Having said that, jet engine owner's manuals allow you to burn gasoline for very short periods of emergency service...you're out of fuel, you're in the middle of the desert, bad people are on their way and the only fuel there is around you is gasoline. You can put some in, fly to where you need to go and drain the system immediately.