ethanol issues

Are you buying mid-grade or premium?

These grades have more ethanol in them, since ethanol is an octane booster.

These grades sell less, so they stay in the ground tanks longer. The longer they stay in the ground; the more moisture from absorbing water vapor the gasoline collects.

Buy "regular." It is likely to have less ethanol in it. It has a higher turnaround rate, which means that it stays in the tank for a shorter time. Thus, it has less time to collect water.

 

Did you accidentally fuel up with E85? It's not recommended. Most available grades of gasoline should run fine, regular being best as Rude person's says.

 

Welcome aboard. I'd be curious to know what state you are in. This is an unusual diagnosis. 10% ethanol is pretty much standard, and hard to believe you could get more than this. But there is such thing as Top Tier gasoline. Here you are talking major brands that meet certain standards: your Shells, Chevrons, Exxons, BP etc. You can google Top Tier gasoline to find the details. Some states may offer 15% ethanol and 85% ethanol, so check your pump to see what you are getting. Some states you can get 0% ethanol, but your car does not need it. Most of us use the standard 10% ethanol with no probs.

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The motor always revs up a tiny bit before it turns itself off at a stop. If it doesn't turn off it means it is charging the battery's. Prius run fine on E50 blends with no codes. Did you buy it used and someone else filled it with a full tank of E85? The only code it will set running straight E85 is a lean burn cold startup code. It will run fine otherwise. The mpg's on straight E85 will only be down 4 mpg from running regular E10 87 octane.

Mike

Mobile on my SGH-i717

 

Although there are some dealerships that operate unethically, I give most the benefit of the doubt. This being said, I'm curious to who they knew the fuel mixture had a higher than recommended percentage of ethanol. Something doesn't sound right. Is your vehicle still under warranty?

 

Wonder if the mechanic measured the fuel's specific gravity to determine the Ethanol content?

If it is indeed full of E85, just drive it and when you get down to 3/4 tank, top it off with 87 octane and the light will go off in a few start/shut down cycles.

Mike

Mobile on my SGH-i717

 

Distributors, NOT refiners, put in ethanol, after they tap their gasoline from the pipeline.

The distributor has to put in a certain amount to premium and mid-grades first, because they have to make the gasoline meet octane ratings.

What's left over, goes in regular. If there is a big order for E85, the amount of available ethanol is less. In that case, there may not be any ethanol in regular gasoline.

 

Not to exceed 10% (at least here) unless you buy ethanol.

 

Ethanol provides less energy per the equivalent liquid volume than gasoline.

Varying from zero to 10 per cent means that you will see a variation of MPG from one fill up to another.

 

True for variations in mpg, however "up to 10%" will not throw a code or manifest the other described engine symptoms by itself.

 

Do you know the actual code that was thrown? Did the engine-light return after the computerwas reset?

Many years ago, some new Prius would have an excess of a sealant that would trigger the engine-light as it was burning off.

As for the behavior of the engine, that interpretation could simply be the new owner experience, when you aren't certain what should actually happen. After all, the criteria for what happens when is quite complex.