They might cease to function, but they are not destroyed,.
The fuel filters and carbs may be gummed up. Clean them up, use neoprene parts and put back together.
Alcohol dissolves parts including neoprene. The neoprene diagram on my turns into gum with holes like Swiss cheese and no longer functions. The diaphragm in the fuel pumps dissolves and will no longer work. Old fuel lines become dissolved and leak.
It costs $100.00 to replace the diaphragm on my ATV. Some parts on old cars can not found to replace them.
i repair these things for a living,you don’t know what you are talking about.
“They might cease to function, but they are not destroyed,.”
One of the other problems is that ethanol will absorb water (humidity) until it reaches about 10% water to ethanol ratio and then drop out of solution.
As posted above, ethanol has a lot higher octane than gasoline so once it drops out, you have a marked drop in octane.
Pre-ignition is the ping you hear from a hot lean engine under load. It does slow damage.
Pre-detonation is fuel detonating prior to the appointed time due to high compression or lack of octane. Pre-detonation removes the tops of the pistons quickly.