If you've ever had a 'performance' car you know that one way to make it run better is to remove the casting flash from intake runners and intake manifolds. Not a cheap proposition, especially when you get into pushing sand-infused clay through the runners to smooth them out. Very common on aircraft engines. It was called 'Extrude Hone' and I don't know if they're still around or not. Lost interest in it.
Some car manufacturers jumped the gun with their perfectly smooth plastic intake manifolds and used materials that wouldn't stand up to the Ethanol in the gasoline. Cadillac was really a bad one. So were a lot of other generic motors cars. I should know because we replaced a butt-load of them. Some of the smaller Fords had problems too, but not as bad. I think now just aout everybody has plastic intakes. Don't know. Lost interest.
Ethanol had some growing pains, no doubt about it. But it does increase Octane rating by a lot. Pure ethanol has an Octane rating Rating of around 119, IIRC (I'm doing this from memory). And RBOB gasoline just won't burn in your car. The Octane rating is too low. The engine would sound like it was about to blow up if you tried to run it. It probably would blow up in short order.
So it has to be blended with something. Ethyl worked but it had some bad side effects. Ethanol is not perfect but it works really well.
I know a guy that drives a taxi part-time because -- He's nuts, IMHO. Contracts with the VA to carry Vets around, especially to the eye clinic in Miami. But he does it. He's got an old Crown Vic with 700 thousand miles on it and he's only ever run regular pump gas. Never done a thing to the engine. Had to put two transmissions in it, brakes, tires, bearings, etc. But the engine has never been touched. Never.
Maybe I should tell him abut that ethanol-free gasoline. He might make his engine last a little longer.
