I find this article rather misleading for those of us that drive cars from the teens to the forties with original engines. Engines of that era are low compression engines that are designed to run on fuel with very low octane as compared to today. An engine that is run on even 87 octane that is designed to run on 40-60 octane needs to have the timing advanced 5-10° to run right and develop the power that it’s supposed to. Also, advancing the timing helps keep from burning up the exhaust valves.
So now you throw ethanol into the mix… ugh!! Many of us choose 93 octane premium fuel to get away from the ethanol, but that is going the wrong direction in the octane world since it’s hard to get the 87 fuel to burn at the right time to begin with. AV fuel has lots of wonderful properties but is even higher octane which is worse yet… for 60+ year old engines.
So there is quite the dilemma as what fuel to run for older low compression engines. Does one deal with the problems of ethanol or the problems of high octane? If you’re lucky like me, I have a gas station the sells only pure gasoline close to my car stash. So if I drive within a 100 mile radius of home I have no dilemma. The problem I have is that I frequently drive my old iron out of that 100 mile radius. I could carry extra fuel in a gas can, but I’m not crazy about having fuel strapped to the running boards. I’d rather be sitting on it. So I often have to choose between ethanol or high octane. In the end, I cringe and choose the ethanol when force to choose.