need help diagnosing an annoying issue

[wall3y3]

Well the small motors are particularly finicky about this, two strokes are even worse but again anything but regular at our altitude is a waste. The higher the octane the less volatile the gas is (harder to burn) which seems counterintuitive but the reason for high octane fuel is high compression engines. With a high compression engine you will get premature detonation with lower octane fuel (knock) which is really bad for the motor. The higher you go the less oxygen the harder it is to burn so as you go up you want lower and lower octane. It does not really cost the gas companies more to make higher octane fuel but people think that it has a higher number it must be better. In Utah if you had a race motor with super high compression then yeah you may need higher octane but any factory vehicle is fine with regular gas - yes you do need it in high octane vehicles at sea level if you have knocking. The fact that gas stations even sell it here is pretty much a racket.
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