ethanol fuel and water

[sandm]

got in the chevy the other day to haul the slot machine up to north vegas for a repair and got me thinkin on the way up there...

I only drive the chevy to the lake, occasional weekend road trip or if I need to go up north vegas with anything. otherwise it's a garage queen. last fill up was 10/16/2020 and it's sitting on about a half tank right now. the fuel that's sitting in the tank is now pushing 4 months old. I've only put 2600 miles on it since 10/2/2019(I have a gas app that I track mileage with) so the gas sits A LOT. I don't treat it. of course I don't treat our leaf blower gas either and it sits in the 1 gallon tank for up to a year but it's mixed as 2 stroke.
truck starts up every time, idles like a champ and have not ever had an issue with running. I bought it in jan 17 and stuffed it in a storage unit a month later due to job transfer and didn't come back to WI to get it for almost 4 months so it's not new to the gas sitting around and in the 4 years I have owned it, spends more time parked than running.

boat has been sitting for about as long. full of gas but it's been treated.

makes me wonder if treating gas can be more climate based or what the "real" length of time gas can sit before becoming unstable and impacts engine performance.

come on summer so we can start burning some

[larry_arizona]

6 months is about what you get on 87 before it starts to taint, 93 buys you 9 months total.

I have a few vehicles I store over winter months and I treat with startron


Sent from my iPhone using Tapatalk

[MLA]

The pump octane rating does not impact or effect the rate at which fuel spoils. So long term storage is another area where using a higher then required octane is a waste.

What I do find interesting though, is a question about fuel and water, from a guy that lives in a desert

With that said, given the closed EVAP system on street vehicles, I would not worry about moisture in the tank. I would also not worry about the fuel spoiling until the 12-18 month range. Now, im not say the fuel is fresh for 12 months, then falls off a cliff. Just saying that fuel can run just fine for months before you would ever know its gone bad. Yes, fuel actually starts to degrade from day one.

For reference, I have a truck that averages less then 3,500 miles a yr and its 28 years old.

[sandm]

What I do find interesting though, is a question about fuel and water, from a guy that lives in a desert

For reference, I have a truck that averages less then 3,500 miles a yr and its 28 years old.

haha. not necessarily a question, more observations and food for thought.

interesting that you have a truck being used in that situation. I wonder if some of the push from manufacturers to treat fuel are on the legal front knowing it would be hard as heck to prove bad gas if something happened to the engine. it's a way the bean counters have figured out how to "push" the public into eliminating future warranty repairs at our expense saving the manufacturer repairs down the road.

it's been beat into my head to ALWAYS use stabil(or some variant) on a boat when laying up but our truck, which is basically the same mechanical parts without some of the emissions stuff, seems to run fine without and mla presents a long term outlook. granted mla's might be luck but also might be the norm if we all followed.

[larry_arizona]

93 is more refined than 87 so it does extend freshness some.

From Sunoco website.

Even in proper storage 87 octane gas can start to degrade in 3 months, 93 octane fuel should last closer to 9 months before degradation is noticeable. Keep in mind that 93 octane fuels are still susceptible to octane loss and vapor pressure decreases due to butane evaporation.

Full context here:

https://www.sunocoracefuels.com/tech...w-octane-fuels

Sent from my iPhone using Tapatalk

[sapiyo]

When E10 gasoline comes into contact with water, ethanol will allow fuel to absorb some or all of that water. This is actually somewhat beneficial, but fuel can reach a saturation point and water can phase separate to form a distinct layer in the bottom of the tank. The upper “gasoline” layer will be depleted of ethanol and have a reduced octane level. The lower “phase separation” layer will be a corrosive mix of water and ethanol. No chemical agent or fuel additive can be added to E10 gasoline, in a reasonable quantity, that will fully prevent phase separation or recombine a phase-separated layer.

[MLA]

Nada, so no bias. https://www.nadaguides.com/Cars/Shop...as-last-longer

So does premium gas last longer? For many, this seems to be a draw of using the presumably higher quality fuel. After all, who doesn't want to make fewer trips to the gas station?

Sadly, there's nothing in premium gasoline that would make it last longer than other fuels from the pump. Since the distinguishing feature is the higher-octane levels, the only real benefit you gain is lowering the chance of engine knocking, which isn't much of a threat on most modern fuel systems.

[larry_arizona]

Nada, so no bias. https://www.nadaguides.com/Cars/Shop...as-last-longer

You sure CNN didn’t write that article? Lol

But fair enough 87 no better than 93.


Regardless, I would add stabilizer for layups longer than 3 months.

In fact, my boat is at the dealer, factory added 1/4 tank of gas 1st week of January and I will be adding startron when I go to dealer this week. It will be mid to late April before I take it home.


Sent from my iPhone using Tapatalk

[996scott]

If it were me, to be on the safe side i would put some stabilizer in when you fill up and not worry about it. Should be good to go.

[jason1973]

if it were me i would run that crap out of your motor. Go waste that tank of gas but then again, i HATE ethanol. I have a SUV that sits in the garage and only used for long vacations and towing. When i know its gonna sit i put 91 NON ETHANOL gas in before i park it. I hate ethanol. it was nothing more than a big sloppy wet kiss to corn farmers and doesn't help the environment as it actually hurts more than helps. A friend of mine works on small engines and he sees more garbage gas problems since ethanol is in use. And in the city where i live we can't buy non ethanol.