With an compression ratio of 10.8 to one,high octane gas should be used.(91 to 92)
The saving grace is that when the knock detectors detect knocking it retards the timing when using low octane gas.
When this happens it cuts down the efficiencies of the engine.
I'm of the Muscle Car era when we were running 10.5 to 11 compression ratios.
If we had used low octane gas (87) back then it would have ruined the engine.
We didn't have computers and knock sensors to adjust the timing back then.
In fact we would use avation gas if we could get it, with octanes of 95+.
The way I see it these engines were designed for higher octane gas.
Get a tank of high octane gas without the ethanol, get someone to time you with a stopwatch. check and see how long
it takes to go from 0 to 60. Then try it with some low octane with ethanol.
Or you can try it different distances, 1/8 to 1/4 mile
I think you will see a difference.
Sam