Concerned over gas going bad

top of the tank with fresh gas after your drive & get a bottle of sta-bil (~$9.-) from walmart or ne automotive shop; works perfect for me in my other car since like 15 years /
5 oz for the prius tank & you're on the safe side /

 

That seems short, maybe 6 months. Look at all these plug-in owners here, they don't seem to be sweating. I wouldn't bother with stabilizer for a few months, just a heads-up: it too has a shelf life, and then whadya do?

I've got a bottle of the stuff that's about a decade old. I've found a local place that'll take it, only issue: you need to drop it off in an approved gas container. You can get a cheapie gallon one for about $10.

 

Some people are, some are not. You'll hear a very wide range of opinions.

But that 1-2 month claim is on the extreme short end, and likely applies to small engines with openly vented gas caps, from the hardest core gas stabilizer proponents. Modern cars have emission control requirements that don't allow such venting, so evaporation is much slower.

Plug-in hybrids are very intentionally designed to go longer between refills than are regular hybrids, so the rest of us can't use them as a guide. Somewhere in the PC archives a few years ago is an article describing GM / Toyota / others' cooperative efforts with CARB to jointly develop standards for evaporation emissions, which drives this fuel longevity issue.

Toyota's flagship plug-in hybrid, the Prime, is intended to go a year before ~5 gallons should be burned off and replaced with fresh. So a regular older Prius must be shorter than that. With all the snowbirds leaving cars behind for the seasons, without piping up about troubles, 6 months does seem doable. Though certain people here are going to dispute that.

Each of my household's cars commonly goes 3 months between refills sometime during the year. For my Prius and Subaru, that is seasonal. For the spouse's near-daily driver, that can be any time of year, especially when it overlaps our longer trips. It's typical trip distance is just 2 or 3 miles, and she runs it down to nearly fumes, so it goes a long time between fills. It is now more than 30 years old, and has been in this use pattern much of the past 15 years, and we haven't yet been hurt by a problem from it.

 

take her for a scenic ride once a week or so, you'll both feel better. no need to feel stupid, it's actually smart

 

That's us, Sunday Drivers.

 

Two year old fuel seems to be ok in a plugin.

 

Don't feel stupid.
Through this crisis, I have wondered just the opposite. Not just gasoline but also threads where people have let their Prius sit so long, their 12 volt has died.
I think starting your vehicle up, going on a point A to point B and back drive, with limited or no stopping is a good idea. Don't know why more people aren't doing it.

If you are using the vehicle weekly...even for those short trips to the grocery store, and you add a longer scenic drive maybe once or twice on the weekend, I'd think you'd be fine. The gas is being burned off.
Quick Google search asking how long can gasoline sit in a car returns 12-15 months.

 

A couple of weeks ago I started up our Honda-engine generator for the first time in more years than I can remember. I had run the carburetor dry, and I *think* I had put Sta-Bil in the gas tank. Didn't add any new gas, but it started on the second pull.