Cold weather got me down!

Excuse my potential ignorance, but why would changing the octane of your gasoline have any impact on your 12 volt battery?
I would surmise if you are having trouble with your 12 volt battery? The problem lies within the 12 volt battery. Might be time to replace.

 

welcome! and, wow.

have you owned the car since new? how often do you drive it?

i voted yes, but thought the poll was about me, not my car. car is fine in the cold, i can barely get my motor running.

i don't think gasoline has anything thing to do with it, but the service department probably things it will run better on 87. what octane is e15?

keep in mind the 12 volt battery only fires computers and relays. hybrid battery starts the engine.

if your 12v froze, it's because it was near dead. a healthy battery won't freeze in temps you can survive in.

 

Well, I don't live in a climate that routinely get's and stays as cold as where you are at.
Even though we do get some cold, cold stretches or nights.
Never had my 12 volt "freeze".

To simply answer your first question, I'd say No, not a lot of reports of people having trouble with Prius in colder climates. They seem to be built to be usable in a wide range of environmental temperatures.

Whatever is causing your difficulties in starting your Prius? I hope it is as simple as simply changing gasoline.

There's a lot of debate about E-15 gasoline, and honestly? I don't know. But for simplification purposes, I'd avoid it if at all possible.

My understanding is that E-15 is actually a slightly higher octane. 88 as opposed to 87.
According to current information and propaganda, using it shouldn't either solve a starting problem or cause a starting problem.

 

Towing should be with front wheels off the ground, no need for car to be in neutral then. Just ensure parking brake is off.

 

I think the service adviser you talked to was not really up to speed. Battery may have gone dead but a jump should have fixed that, if you know how to do it safely. Once they jumped it and got it into "Ready" mode, it probably would have drove away.

Low temps will impact a 12v batteries capacity, so if it was weak then maybe it failed, but just as likely would have been an interior light left on that drained the battery temporarily.

The only thing I can think about changing gas is that a higher concentration of alcohol may have allowed for more water in the tank "possibly" freezing something in the fuel system. However this is highly unlikely.

 

no, it doesn't run on the 12 volt battery. there's a huge 200 volt battery under the spare tyre.

 

Exactly. A 12V battery needs to be nearly completely discharged in order to freeze in common cold weather.

 

Very common for a weak 12v battery to need replacement in cold weather. Cold is good for the life of the battery, but bad for the power output. So during the summer the 12v batt is weakening, but the hot weather allows a decent power output, until it get's colder and then Wham you need a new 12v.

You're probably better off using normal E10 if you can get it, but E15 probably OK. I don't think Toyota approves E15 for 2010 models, could cause some codes to go off, not sure.

 

On batteries....

Heat kills your battery. Cold is when it is the most taxed. Harder starts = more CCA needed to do the job, and a weak battery shows it's condition when under load.

Normally, you'd check your battery in the summer, and I know the Prius has its 12V more sheltered, but this is why it seems your 12V struggles or even fails in wintertime.

 

It's kind of buried in the Owner's Manual, but Toyota says "do not use any fuel that could contain more than 10% ethanol, such as E15" It's under section 6-1 Specifications, Fuel Information. This is from my 2013 manual...

CURIOUS FOLLOW-UP: I remembered that fuel specs are also printed on the fuel filler cap, so I checked my 2013 filler cap, and it says no more then 10% ethanol per the owner's manual. Then I checked the cap on the 2014 we also have, and it allows E15! And the manual for the 2014 states E15 is acceptable also. I guess the Ethanol lobby finally got to Toyota!

Still, fuel/engine and 12 volt battery are not related, so I'd say you just hit the perfect storm of a dead 12v battery AND a poorly running motor at the same time. Your poorly running motor is certainly due to the fuel choice you made. You never said how many miles are on this car. If you're at 100K miles or more, you probably need a good tune up (spark plugs, throttle body cleaning, etc.) to get the motor running properly again.

 

E15 disclaimers are simply a liability-avoidance tool that the automaker uses. It's industry wide. Why accept extra expense primarily caused by lack of understanding and information?

 

First, it sounds to me like it was the original battery. It was time to replace it. If you discharge a lead acid battery the electrolyte becomes more water, less acid. The temp. the battery will freeze at rises. Still, in Iowa, I doubt very much your battery froze. What was the temp? Well below 0F? So, a battery that needs to be replaced will freeze at a higher temp than a "good" battery. But I still doubt it actually froze. But it probably did need to be replaced.

Second, the fuel you use has -NOTHING- to do with freezing the battery!!! Or with the battery failing. It was old.
E15 will probably work just fine in the Prius, though Toyota strongly recommends use of E10 max. You will get better mileage with E10, but E15 will probably burn cleaner. You pays your money and you takes your chances.
I would follow Toyota's recommendation. E10.

 

is e15 cheaper, based on energy and mpg's?