94 octane gasoline = quieter ICE

It is common practice around here.
Around here Premium is always a minimum of a dollar a gallon more at every station except Sams Club

I just won’t ever buy Premium fuel and 92/93 octane is very rare as well to begin with
99% of stations 91 octane is premium with a few 90 octane places

 

Off topic but I was looking for that video.
That steep climb video is interesting in view of the Lion Air accident.
The test pilot must have the anti-stall MCAS system disabled, I assume.

 

Card transactions are to the penny.

 

Is it also common to see mid-grade at a dollar more than regular ??
THAT is what caught my eye in the original picture.

 

Is all your premium ethanol free?

 

Up here Chevron highest octane (94) is, see pic in my post #74:

94 octane gasoline = quieter ICE | Page 4 | PriusChat

I tried it once or twice, didn't notice any significant difference.

 

It’s about a 50% chance

93 is never ethanol free 91 almost always is e free

But 87 is efree at about 1 out of 4 outlets

 

How do you tell? You ask, they post on the pump, you test?

 

It’s legally required on the pump but...

In my area e free is a big deal, certain stations list all grades as e free right on the big sign

Other stations list specific grades with ethanol content from zero to e85

It’s pretty obvious what you get
Heck there is even an online puregas gas buddy like site that lists e free and another that lists only e85

 

Yeah, Wisconsin has 936 ethanol-free gasoline (E0) sources & comprises 7% of all the E0 sources in the U.S. & Canada.

 

The majority of limited available ethanol-free gasoline (E0) sources in Canada is 91 octane. British Columbia has quite a number of 94 octane E0 sources, along with other octanes of E0.

 

There ya go!

 

87 octane E10 blend is a wide octane spread of 114 octane ethanol molecules & 84 octane gasoline molecules. It is the 84 octane gasoline molecules that knock in an 87 octane designed gasoline engine. 91 octane E10 blend is a less wide octane spread of 114 octane ethanol & ~ 88 octane gasoline molecules, contributing to less knocking. Now, if you could have found & chosen 88 octane ethanol-free gasoline(E0), all the gasoline molecules would have been 88 octane & probably would have less knocking, been quieter & provided higher MPG.

 

That's an interesting theory.
But individual molecules do NOT "knock".

 

Its mathematics: 10% 114 octane ethanol molecules, blended into 90% 84 octane gasoline molecules give a designated 87 octane E10 blend. Individual gasoline molecules may not knock, but millions of 84 octane gasoline molecules are knocking in every cylinder explosion in an "87 octane gasoline" designed engine. "samspade2" knew this, but had to squawk about "theory" & individual molecules, for some reason.

 

The reason IS......that the way you stated it is misleading and wrong.

In normal operation, there is no "explosion"; there is a controlled burn.
The mixture of different molecules helps prevent an explosion.
Just the presence of nitrogen and carbon dioxide in the mixture tends to slow down the burn.

And finally, "octane" is a measure of a characteristic of the whole fuel mixture.
A single molecule does not have an "octane number".

 

There are two methods to lab-test for octane, the Research Octane Number (RON) and the Motor Octane Number (MON). The U.S. and Canada post the arithmetic average of the two numbers...RON + MON ÷ 2...and call the result the Anti Knock Index (AKI). The AKI is posted on the pump. Other parts of the world use just the RON which runs 6 or 7 numbers higher for the same gasoline.

The price spreads listed above for different AKI levels is just goofy. Here in the Seattle area we currently have $2.99/$3.19/$3.29 for the three grades of E10. The top grade is usually 91 to 93 AKI.

 

It certainly isn’t uncommon

Most stations charge about a quarter less for mid grade than premium,
So $0.65-$1.00 more for mid grade is quite common.

Only place that is sometimes bucking the trend is the Indian Casino, got gas for $1.99 a gallon today, noticed mid grade was $2.09
everywhere else 87 was at least $2.17 on up
Cheapest mid grade in town is at Sams club for $2.75 a gallon

 

We could probably clear up a lot of debt, be better off, if everyone used the spec'd gas?

The percent of cars that actually need the higher octane is so low, and yet there the various options stand in a row, with equal billing...

 

@mendel, is that you looking into the backup camera?

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