[Hal Copple]

I only know what i read. One of the car magazines several months ago ran an Octane and gas test on a "built" 340 Mopar. I think it was Popular Hotrodding.

Dispelled some of my long held cherished beliefs about gas, octane, timing, and power.

They found that indeed, as the gas "quality" increased (they also ran tests with octane boosters), starting with 87 octane, going up to 114 octane, that the motor did make more power, i think like 15 more horses as i recall over baseline. They also found that on this specific engine, trying to increase the timing, to take advantage of the higher octane, only dropped the power a bit.

It seems that internal combustion is a very complex thing, and it is far too simple to state that all higher octane does is burn slower.

This article did change how i run at the drag strip, i do run race gas, and leave my timing alone. If the original poster noted his car ran better, perhaps it is because (at least here in SC) we are still getting winter gas, with its higher Reid vapor pressure, and i can tell exactly by driving when they start in the fall, and cease in the spring. My custom engine for sure runs much better, especially in hot stop and go traffic, with less fuel percolation, on the summer blend.

I often put in about 10 bucks of 100 octane, which i can get at the pump here, it does seem to improve my winter gas drivabilty some, by making the gas less volitile.