Ethanol free gas?

[MossRoad]

As mentioned many times, I've been using E10 87 octane since the 80s in everything I own. I've never had a fuel/water issue. Cars rotate the fuel through usage. However, all of my small engines, with the exception of the chainsaws, can and do sit around for months and months, and even years, with E10 and no problems.

The only reason the chainsaws don't sit is that I run them dry through usage. After X tanks of fuel, I'm done for the day and don't refill them.

Weed eaters, snow blowers, pressure washer, lawn mowers, tractors, log splitter, tiller.... never a fuel issue.

I also store three 6 gallon plastic cans of E10 87 octane all winter long. No snow. No usage. Gas sits. It'll get used in the spring.

Good luck to all, however, water in E10 issues are not a problem here.

 

[devodad]

Best practices would be to run the octane rating recommended by the manufacturer 100% of the time unless the engine has been modified.

I can't think of many small engines that call for 91 octane.

No they don’t call for 91 octane. They call for regular 87 And then the dealers will recommend other expensive additives to counteract the ethanol and at the same time boosting the octane.

 

[yomax4]

There are a ton of Ethanol Treatment additives like Stabil that supposedly help the ethanol fuel maintain. Some others use a couple bottle of Heet red bottle to help with any potential water problems. Not sure if it all works as intended but I use some here and there in my plow truck which sits for 6 months every year.

 

[dodge man]

Stihl says 89 octane. I’ve had three issues with Ethanol fuel going bad. In one case it hadn’t sat that long, maybe 6 months. The other cases they had sat for more than a year. All small engines.

 

[Username Taken]

What happens with chainsaws a lot is when the gas sits, the gasoline can evaporate but the oil doesn't. Even inside the chainsaw.

And that can make for a too rich oil to gasoline ratio. Which, IMHO, is often way too rich anyway. My 200 HP Yamaha Outboard ran at 200 to 1 at lower speeds. But chainsaws don't see a lot of idle time. Whatever

Bought a chainsaw at a garage sale one time for $20. It was good one, too. An older Stihl.

The guy said he couldn't get it to start and run right.

I put straight gasoline in it, about a pint. It started up and ran like a champ. Still is, AFAIK (gave it to my brother)

Octane is good for one thing, to combat pre-ignition. That's it. Period.

Gasoline engines compress air AND gasoline in a mixture at the same time (unlike diesels that compress only air).

Compression creates heat and it can cause the gas mixture to prematurely ignite, especially when the engine gets toastie. Not good. Octane boosters keep the gasoline from igniting until the spark hits it. Got nothing to do with anything else

But if Stihl says to run 89 Octane, probably a good idea to do so