88 octane unleaded without ethanol less expensive than 87 octane with ethanol?

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I've got a question about gas sold at Casey's General Store. They sell an 88 octane unleaded, which sells for 10 cents a gallon less than their 87 octane unleaded. The 87 octane contains 10% ethanol, while it appears the 88 octane contains no ethanol. I was under the impression that straight gasoline without ethanol was more expensive than gas with ethanol, so how can the 88 be less expensive than the 87? I was told this morning, and I don't know how accurate this is, that the 88 has some other additive. There is no indication on the pump of this gas having any additive like the pump with the ethanol containing gas has, and I thought it was a law that any additive had to be posted on the pump. Is there a loophole in the law that allows for this additive without listing it? I find it hard to believe that straight gasoline would be less expensive than that with ethanol...
 
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I suspect that since 10% ethanol raises the octane number of gasoline roughly 3 points, what you are dealing with is actually 91 octane MINUS the eth. All other additives are required by law, unless of course someone decides to do something extra.
 

Bud_One

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Wow... we have a new QT gas station by my house that has 90 octane ethanol free , but sells at $4.22 @ gallon vs 87 octane with 10% ethanol at $3.67 @ gallon.
 
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Sep 17, 2002
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Lakeville, MN
May want to look at the pump closer. 88 Octane here is all E15.

I've got several stations in this area selling Super 88 (as they call it) or E15 for 40+ cents a gallon less than regular E10 87. I use it in my 2016 F150 and 2021 Explorer when the price difference is that great as if offsets the slightly lower fuel mileage I get. Interestingly, the Octane Adjustment Ratio (OAR) in my truck goes the opposite direction - down - when I use E15. Truck runs fine on it though...
 
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Mahzurrah!
Ethanol free is all over the map here. Bought some at Quik Trip two weeks ago, it was only 4 cents more per gallon but since I get 8 to 9 percent better mpg on it a no brainer. I have often seen it priced more like an extra 30 to 40 cents a gallon so I don't know what was up.

I've been buying premium 91 ethanol free at a nearby Casey's as well. It's priced about the same as other premiums here, but with GetUpside I'm getting a discount and again better mpg to boot so a good buy.

Not a fan of Casey's 87 regular at all though. Anecdotal but I've had some issues with it along with other family members.
 
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A Sheetz station near me has E10 in 87-89-93 octane, 88 octane E15, 90 octane ethanol free, flex fuel and diesel.

Not all choices are at every pump. The pumps with diesel also have ethanol free 90 octane.

The dedicated blue fuel line is for 88 octane E15. The dedicated red fuel line is for 90 octane ethanol free.

All pumps have 87-89-93 octane E10.

The more ethanol there is in fuel, the more it effects fuel economy in a negative way.

There are the rare users that tune a WRX or whatever to use flex fuel and take advantage of the higher unadvertised octane. 100+
But there is less BTU energy in ethanol fuel vs ethanol free fuel hence the gas mileage penalty.
 
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I tried Sheetz 88 e15 in my ram this past weekend for towing. Towed fine, but my usual 11.5 mpg went down to 8.9 towing a 7k travel trailer.
 
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Nokesville, VA
It's interesting when people say that they lose so much fuel economy using E10 or E15 gas.

Assuming that ethanol contributes NOTHING to the combustion process (which is not true), the most you could lose is 10% running E10 vs ethanol-free.

And the most you could lose is 5% running E15 vs E10.
 
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At least for me, I've never claimed it to be a giant percentage. Once you've run enough E15 vs E10 and have records, its easy to see that I do get lower fuel mileage on E15. Statistically, its almost 2% lower. I'll also note that despite the higher octane rating, my truck doesn't see it that way and actually reduces the timing etc... on E15. Not just as simple as energy content.

So for me, at current prices of 3.99 a gallon for 87 E10, if E15 is more than about 8 cents a gallon less, then it makes sense to run. Many stations here are only 3 cents cheaper a gallon through...
 
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Jun 19, 2020
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Iowa
In my area Casey’s 88 octane is e15 and intended for use in 2001 and newer
^^^^^^agreed, the Kwik Star's around me have 88. The only 88 I've seen is E15 hence it is cheaper. If 87 E10 is within $0.05 / gallon I go 87, if it is more I go 88... Mileage goes down some with 88 but not enough to worry about if price is not close.

just my $0.02
 
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May 7, 2004
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Nokesville, VA
Wow, here in southeastern Wisconsin it is nowhere near that large of a difference.

I don't get it, it's not like Virginia produces much ethanol. Just checked, Sheetz is still $3.99 for regular and $3.69 for 88/E15.

And my Chevy Volt likes the additional octane from 88/E15 (it's specified for premium. It can run on regular with a drop in fuel economy. The drop in fuel economy is nowhere near large enough to make up for the 69/cents per gallon extra cost of premium).
 
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It's NOT recommended by Honda. Only use e10 or less. The 88 octane part would be okay but the 15 percentage of corn is a no go.

It depends on model year, for example many newer Honda vehicles have it stated in the owner's manual that they can accept up to a 15% ethanol blend.
 
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