In Packard, I would much prefer ethanol free fuel, because it doesn't go bad as quickly while sitting.
In the S600, Mercedes specifically recommends ethanol free but requires high octane. Hard to find that, and I end up buying 93 octane with ethanol as that's all I can find locally.
But in my Tundra? No real difference.
So, regular car? Don't worry.
High performance or antique car? Different matter.
I try to use it in small engines ( lawn mower , edger , etc. ) .
I think it helps to avoid ethanol gas in small engines. Most all the small engine manufacturers recommend an ethanol fuel treatment like, "Ethanol Shield" if you have to use it. Ethanol free motor fuel is difficult to find, and very expensive if you do.
So for small engine use you're almost better off to buy either VP or Tru Fuel at Home Depot or Lowe's. It's more expensive, but all you have to do is pour it and use it. By the time you screw around buying and treating the ethanol gas you're further ahead. Plus the stuff has a 2 year or more shelf life. Naturally if you have to mow 5 acres every week, that's a different story.
Here many of the local stations sell Av-Gas because of all the high performance boats around here. But again the stuff costs a mint.
OPE are the only engines that I use it in. Can't justify the cost otherwise.
In fact, my vintage 1988 Homelite trimmer still has the sticker that says "Do not use Gasohol".
I can get non-ethanol in 87 and 90 octane locally. The same garage sells 110 octane race gas, though I haven't a use for that myself. Yet.
I usually buy 30 gallons of it at a time because the only local station that sells it is 25 miles away. I try to use it exclusively in my small carbureted engines and outboard. It can save you the trouble of having to take the carb apart to remove the gum and varnish left by ethanol fuels.
I wouldn't pay the premium to use it in a vehicle unless it was going to be parked for months.
In my fuel injected vehicles ethanol blend is not an issue. And all my small carbureted engines ethanol-free is all I use and a fuel stabilizer. I have not had a carburetor related issue in years nor any starting problems after seasonal storage
Energy density of ethanol is less than that of gasoline, which in theory should lower your MPG. It may be unnoticeable with E10 vs. E85. Other than that, it's said that it gums up carburetors, deteriorates rubber fuel lines, and generally turns bad over time, but I've never experienced it.
Make your own non ethanol gas, just add some water, the ethanol comes out of the gas. And then it works great in small engines. After doing this my lawnmowers startup without having to have me clean out carbs.
since most corn being GMO is unfit to eat they gotta do something with it. non-ethanol is surely better BUT at what cost, so i use it in my carb'd small engines that run seasonally + sometimes infrequently. my traded hardly porkster lost 5 mpg's when shell's 93 octane added corn pea!!!