my Prime sipped some gas today

At some point, it is likely to run for the sake of keeping things fresh. Not sure what the criteria is for this generation though.

My gas is from mid-July with "only" a distance of 2,500 miles on this tank, so I can't relate.

 

could be. it might be a good idea not to let the gas get too old, idk.

 

pip manual recommends using up gas every 6 months. now that i have a fairly reliable routine, i'm only putting in 3 gallons at a time.

 

Make sure you use ethanol free and or staybol additive. That is probably bad gas from Dec

 

Remember low fuel in tank allows more condensation in it.

 

Only if ambient air can enter.

Bob Wilson

 

The ICE will start under certain conditions even while in EV mode, if the battery pack is too cold, too hot, under heavy current load, SOC is too low, SOC is too high while going down hill/braking, etc. The outside temp being 40 degrees is most likely why the ICE started.

Not sure what will be the best advice when it comes to those who never drive the car in HV mode, other than don't let the gas sit unused for more than 6 months. If it were me I'd just drive it in HV mode until I needed to fill up.

 

Putting 3 gal at a time would seem to provide plenty of opportunity

 

prius fuel system is sealed. hopefully, older advice from pre emissions days doesn't apply anymore, but i'm no expert.
when i was a teenager, i used to drive around with between 0 and one gallen all the time.

 

the problem with plug ins is how long the gas stays in the tank. so you drive a long time between fill ups, or keep topping up after a certain level drop. but there is nothing in the manual for pip except not letting gas get older than 6 months.
some here recommend a fuel additive like stabil.

 

You don't really want to have Winter formula gas in your tank during the Summer and the reverse is true about Summer and Winter.

 

Would this still be the case for people in Texas where we really don't have a winter? It's very rare for us to get below freezing.

 

Do they sell winter-blend gas in Texas?

 

I've never paid attention. Are they supposed to put up signs or something?

 

No signs, you'll just notice you're getting worse gas mileage and assume it is cold weather...winter blend in warmer weather still yields worse fuel economy...

Bottom line is folks, if your gas is getting old better burn it up in HV mode or expect repairs on the fuel system. Although the fuel system is sealed, leaky gas caps and so on will eventually occur after some time. The Prime already will get better gas mileage so it takes longer to burn in HV mode anyway. So if you don't drive that much something to keep in the back of your mind...

 

Not in areas where I have lived (all northern states). Transitions are seamless. It all happens in refineries, so us consumers at pump are not notified. That said, usually in spring/early summer when they switch to summer blend there is some price hike due to cost of summer blend being higher than winter blend. And opposite is true for winter changeover in fall.

 

Car fuel tanks are much better sealed than the can used for the lawnmower gas. So fuel stays 'good' longer in them. IIRC, the Volt will go a year between fuel ups before starting a fuel maintenance mode to burn off the old fuel.

The systems in place to reduce evaporative emissions will stop some humidity from getting into the tank when air enters to replace used fuel. The volatile compounds that came off the gas and got trapped by the carbon canister will come off the carbon and re-enter the tank with that air. The little bit of humidity that gets into the gas will be picked up by the ethanol in most climates of the US. The tank itself is likely plastic.

You'll see the fuel efficiency difference, but it isn't something to worry about. The difference between the blends is to help older cars(think carburetor) start in winter, to improve emissions, and to let the refineries get rid of stockpiles of less valuable things(butane gets mixed into winter gas).

Diesel is a different story. Summer bend diesel can gel up in the fuel lines with colder temperatures.

 

I think you need to fire some more gas before filling up! Sip is not enough, let's have a drink!