Marine engines with carbs and fuel tank hoses are getting destroyed by the ethanol so selling there makes sense.

How exactly is the ethanol destroying the marine engine?

I've come across two fuel tank issues. The first is the same as the potential problem with biodiesel. An old tank can can have a build up of, well, gunk in it. It stays put until the stronger solvency of the different fuel starts to loosen up. It breaks loose and then can clog up stuff.

There other is only with fiberglass tanks. The ethanol dissolves the resin, which then gets into things and makes a royal mess.

I guess the ethanol can bring in more moisture that might lead to corrosion. But then how do carbed boat engines kept on the water deal with the problem?

The ethanol seems to attack the old black hoses and zinc aluminum casting and brass in the carbs usually in the older motors. My brother was saying that when the fuel is left in motorcycle gas tanks they end up 1/3 full of water at the bottom after a few months of sitting. He said a test is to take a glass jar with gasoline in it with a pin hole in the lid and it will change to water at the bottom in a few weeks. I poured old gas out of a friends small outboard and it came out black, it still ran but looked nasty and that was just gas in the motor's built in fuel tank during the summer.

Flex-Fuel vehicles feature special plastics and rubber that won't be damaged by the ethanol, and that must include all gasoline engines, including marine.

Thanks for the info.
Except for what I mentioned, the hows of why it hurt the engines isn't regularly expressed. Repeated comments of 'it destroys engines' without seeing any whys had me doubting there was a real problem here. Fiberglass resin in the engine would destroy it, but I saw that as a problem with the fuel tank, not the engine itself.

Don't know about the boating industry, but ethanol, and even biodiesel, resistant fuel lines have required on cars long enough that if you don't have them now, it's probably a good idea to replace them anyway do to age.

Was gas that sits or sat, I add isopropanol too. IPA isn't hygroscopic like ethanol. It won't absorb moisture from the air, but will let any phase seperation from the ethanol's properties remix.

I had problems with the weed trimmer this year, but I never emptied the tank and ran the fuel out between seasons. Ethanol might make the recommended maintenance more essential, but it was recommended before ethanol for a reason.

I'd love to be able to get straight gas, but if it's between MTBE and ethanol, I'll take the alcohol. Of course modern cars need neither for clean emissions, and few carbed ones on the road don't have a large impact. Over 10% ethanol is pure political pandering.

I just don't think rhetoric and heavy emotional responses help in a discussion.

My friend swears his 2005 V6 Camry runs worse since we started getting E10. I always ask him if he has tried 89 octane like Toyota recommends for the car.:p

Well said.

LOL. So you didn't have E10 in 2005? I think it's been universal around here since before then.

Apparently the ethanol and water it absorbs turns acid and attacks the older aluminum alloys. I haven't used any of the E10 in my 78bmw R100S but I can double check with my brother who works on bikes all the time. I have a friend/client that imports dellorado carbs and he sells a lot of jets that are replacing ones corroded by E10 gas.

I'll have whatever she's having.

I thought Pa had E10 before 2005, but it may not have been statewide mandatory.

I do remember coming across info of the ethanol being bad for an aluminum engine, but couldn't remember why it was. I actually thought I was thinking of sodium hydroxide(lye), which eat the metal like a strong acid would be pictured doing.

I don't know of any modern aluminum auto engines that don't use iron sleeves in the cylinders.

I couldn't agree more, Costco gas is a real game-changer when it comes to saving on fuel costs! It's a fantastic choice for multiple reasons:

Consistently Lower Prices: Costco's competitive pricing means you can often fill up for less, which is always a win.
Quality Fuel: They source their gas from reputable suppliers, so you're getting good-quality fuel.
Refund Checks: Getting a refund check based on your total purchases is like an added bonus. Who doesn't love a little extra savings?
Credit Card Perks: The perks from your Costco American Express card sweeten the deal even further, especially with that 4% gasoline purchase return.
Membership Benefits: Plus, as you mentioned, the membership itself pays off in savings, making the card essentially free.
It's a winning combination for both your car and your wallet! 🚗💰