Can gas go stale in the 2020 Prius Prime hybrid plugin?

Now that 2021 is real, I can say the last time I bought gas for my Prime was two years ago (Dec. 13, 2019), and it is still 3/5ths full. I either need to siphon the stuff out of there, or go for a decent gas-only drive. Stupid COVID. I do hope 2021 will see some driving vacations across the country - maybe later in the year.

 

How many total miles driven per year?

 

It is what you make of it. Just drive somewhere, treat yourself to an out-of-the-way destination.

We found a butcher (who makes absolutely fantastic blueberry wildrice sausage) that's a day-trip to reach. We drive there, fill the cooler with various meats, then do a little sight-seeing before returning back home. No big deal. Gas consumed for a worthwhile cause. We also baked cookies and delivered them to friends & coworkers around the metro area. The outdoor drop-off was greatly appreciated by everyone involved. They got holiday goodies and we got to visit in-person for a change, as well as use up old gas in the tank.

Think about what you'll do after Covid barriers pass. You'll still have to use gas from time to time. Why not find useful way of doing it?

 

WRONG. While it does not "gum up" as quickly, it DOES degrade if you let it sit too long.

AND.....if you buy E0 from a station that doesn't sell a lot of it, the gas in the tank in the ground might be older than what you have in your tank.

 

How long?

It must be a loooong time. All we have had available here for the past 20 years is E10 and I have never heard of anyone dealing with that. Perhaps it is with other offerings, not the blend with additives sold here.

 

Siphoning gas out of a Prime is a bit tricky, since you have to get around the vapor emissions mechanisms. You can't just stick a hose down the filler pipe, like in the old days.

 

I was kidding about the siphoning. It would be more of a pain even if successful. Maybe a couple round trips to Rockford or Racine (buy some Kringles?) would do the trick.

Normally, we'd put 6,000+ miles on the Prime with a couple vacation destinations. This year it was just "charge-er-up" dozens of times to make it that 3 mile round trip to work and back. At least, I wasn't a stay-at-home worker. And I can honestly say I wasn't polluting the air behind my car very much. That's at least a win.

Used gas a bit to:
1. Obtain a new driver's license and Real ID to a facility out of our area so I wouldn't wait outside in a line for 6 hours. As it was, I waited in line for 4 hours, 3 of them outside. Brrr.

2. Trip south to Starved Rock State Park.

3. Trip up north to another state park.

All-in-all, that took 2/5ths of the gas tank. My complaint? The Prime is far too efficient.

 

Not sure if this comment was overlooked by many here, but I think this is an excellent point. For anyone who uses the ICE so rarely, this seems like a perfect use case for the Charge Mode feature. Basically convert some aged gasoline into electricity, rather than just driving somewhere further for the sake of it. Weekly may be a bit more often than necessary IMO, but whatever works best for your situation. Could also just skip charging for a few days and run HV.

Was the person who said they paid a shop to swap the gas for real? Can’t be...

 

That makes a lot more sense than charge mode.

It is amazing, isn't it.

 

It depends on conditions. A couple of years maybe.

I KNOW this because E0 gas has been around a LOT longer than ethanol blends and carbs have been gumming up all that time.

 

YouTuber, The Car Care Nut, has some good advice for Toyota Primes. The first few minutes talks about ethanol added gasoline and corrosion:

 

This guy obviously knows what he is talking about BUT he gets a bit carried away with his "corrosion" claims.
Ethanol in gas makes it tend to DEGRADE a bit faster than pure gas but E10 that is a year old is no more "corrosive" to parts that are made for it than fresh E10 right out of the pump. It just is NOT.

His conclusion is right on.
Too bad that he got that one little detail wrong......but it really doesn't make any difference.

 

Ethanol is corrosive to aluminum over time. However, some water in the mix makes it same for the metal. Some markets even offered hydrous E15. The ethanol in it wasn't taken to 100% purity before mixing, but to around 95%.

The water itself can be corrosive to other materials, but the real culprit is likely something in the water. All gas station tanks have some water in them. The delivery trucks don't stop for the rain. So most of the water is run off that has picked up salts and other compounds making it acidic.

 

Some of your theories are truly amazing.
That same "runoff" would go into the tank with E0 also.

 

Geez, why so much worry about stale gas .... why not just pump a couple gallons only into the tank if you seldom if ever drive with the ice on. That way - if you ever ARE going to go some place farther away, you just pump a couple extra gallons into the mix and then you're back to Just Two Gallons.
.

 

OCD.

 

Um, it does.
The Truth About Water in Fuel Storage Tanks - CStore Decisions
Drivers Beware: Rainwater may seep into underground gas tanks

As for the more corrosive stuff in the water, it can be picked up from the environment, or from the fuel systems it travels through.

"Many impurities can be found in fuel-grade ethanol including sulfuric acid, acetic acid, water, and sodium chloride. "
http://amet-me.mnsu.edu/UserFilesShared/MnCAR/DOE%20Papers/E20%20Material%20Compatibility%20Testing/MSU_E20_Plastic_Material_Compatibility_Study_2-21-08_Final.pdf

" The aggressive ethanol and butanol fuels contain contaminants that potentially could be found in the liquid fuel infrastructure system at varying levels. Aggressive ethanol contains 99% ethanol, 1% water, 5 ppm sodium chloride,25 ppm sulfuric acid, and 75 ppm acetic acid"
https://escholarship.org/content/qt6xn8z1v5/qt6xn8z1v5.pdf

 

Put some tc-w3 2 cycle oil in it and fill it all the way up with premium fuel. I think the mix is 2 ounces per 5 gallons so 4 ounces for a full tank. A full tank has less issues than a partial tank when it comes to these things. Less exposure to air helps a lot and the tc-w3 oil will lubricate any fuel burn you do preventing damage to the engine etc. If you need to get rid of the tannins produced. Just get a bottle of fuel cleaner and stop using battery until you get through a tank of fuel.

 

A friend of mine asked me about whether or not the gas would go stale after I told him that I had barely used the ICE since July because we haven't taken a road trip since last January due to Covid. I thought that was a good question so I thought I'd check here at Prius Chat. Back in April when gas was down to $1.40/gallon, I thought I'd run on gas only, not recharging, in my 2018 Prius Prius for an entire tank to see what my city mileage was (52.5). After filling up the tank in July, I've only driven around 35 miles on gas since then.

Based on the many answers in this discussion, it sounds like it hasn't hurt anything by not using gas for so long but that it probably wouldn't be a bad idea to do so in the next few months. Some people suggested doing a road trip, but it sounds like the easiest thing to do if you don't have anywhere special to go is to just not recharge and then drive in hybrid mode without recharging until you need to buy gas again. Maybe down to a 1/4 tank, or most of the way? Does that make sense? Thanks.