Ethanol Fuel Tester

The tester is simple to use. Just add water, gas, shake and wait for things to settle..

Perhaps this will put an end to the question where can I get ethanol free gas.

Locally, only 91 octane is ethanol free and have a separate pump/hose to dispense. Mid-grade 89/90 octane types just have more ethanol to boost the octane levels.

Use tester and confirm if 91 octane is ethanol free.
tester

You really don't need any special tool other than a plain old test tube and a sharpie marker.

Just but about half an inch of water in the tube.
Make a mark at top of water.
Add gas till almost full.
Shake it up good.
Let it sit for about 4 minutes.
If the water amount has increased, it had ethanol and or water in the gas which has combined with the water and is now settled or is still settling out of the gas.

And where did you get the info that higher octane level gasoline is the result of adding more ethanol?

Still got one from Briggs & Stratton from 30 years ago!!!!!!!!!!!!!

(quoted from post at 17:52:14 05/24/22)
You really don't need any special tool other than a plain old test tube and a sharpie marker.

Just but about half an inch of water in the tube.
Make a mark at top of water.
Add gas till almost full.
Shake it up good.
Let it sit for about 4 minutes.
If the water amount has increased, it had ethanol and or water in the gas which has combined with the water and is now settled or is still settling out of the gas.

And where did you get the info that higher octane level gasoline is the result of adding more ethanol?

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ust do a DuckDuckGo search and you can read as many articles on ethanol octane numbers as you like.

I just catch a transport driver when the are unloading and ask what stations are pure gas.

I know what the octane rating is for ethanol.

The question was about the octane rating of mid-grade 88/89 and premium (90/91).
And what is done to the gas to get those higher octane ratings vs regular 86/87 E10.

Somewhere Geo got the info that they add more ethanol.

I test allot of fuel its rare I detect Ethanol. I just got 25gal I will try and check it tomorrow.

They use to make 2 grades of gasoline.
87 and 91.

In the southeast Racetrac was one of the first that started using ethanol.
So if you bought 87 gas at a Racetrac station you were really getting 89 gas.
90 percent 87 and 10 percent ethanol.

As ethanol became more popular refiners started making 84 gas and stopped making 87.
So today the only gas made in the southeast that I know of is 84 and 91.
Yes they make differant grades for high altitudes but I am limiting this to east of the Mississippi.

90 percent 84 and 10 percent ethanol gives you 86.8 gas.
This is what they sell as 87.
60 percent 84; 30 percent 91 and 10 percent ethanol gives you 88.9 gas
This is what they sell as 89
90 percent 91 and 10 percent ethanol gives you 93.1 gas
This is what they sell as 93

For pure gasoline they blend 60 percent 84 and 40 percent 91 to get 86.8 pure gas.
They sell this as 87 pure gasoline.
100 percent 91 is also sold as 91 pure gasoline.

Nice explanation John, I sort of knew that gasoline changed to make use of the higher octane in ethanol, but never had the numbers laid out so well as you did.

Fortunately we havent had to test gasoline here in Minnesota for several decades, as nearly all has been 10% ethanol, a good thing in my opinion. Its nice to see the 15% showing up now, hope we get to the even more efficient 25% sooner than later.

Paul

When did octane become a big deal for more. If I remember right higher octane gas back when was for the higher compression engines to help keep them from dieseling when shut off. If that is the case then there is no more HP or otherwise in higher octane gas. Just would be the opposite to make it not diesel it has to be harder to fire not really anymore power.

(quoted from post at 02:36:42 05/25/22) Nice explanation John, I sort of knew that gasoline changed to make use of the higher octane in ethanol, but never had the numbers laid out so well as you did.

Fortunately we havent had to test gasoline here in Minnesota for several decades, as nearly all has been 10% ethanol, a good thing in my opinion. Its nice to see the 15% showing up now, hope we get to the even more efficient 25% sooner than later.

Paul

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ore efficient? afraid not.

(quoted from post at 19:12:38 05/25/22) When did octane become a big deal for more. If I remember right higher octane gas back when was for the higher compression engines to help keep them from dieseling when shut off. If that is the case then there is no more HP or otherwise in higher octane gas. Just would be the opposite to make it not diesel it has to be harder to fire not really anymore power.

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ot primarily for preventing run-on.. Higher compression yields more power, but it also can lead to detonation (vs controlled burn) which can melt pistons, break rings , ring lands, et. This is primary reason for high octane.

(quoted from post at 23:36:42 05/24/22) Nice explanation John, I sort of knew that gasoline changed to make use of the higher octane in ethanol, but never had the numbers laid out so well as you did.

Fortunately we havent had to test gasoline here in Minnesota for several decades, as nearly all has been 10% ethanol, a good thing in my opinion. Its nice to see the 15% showing up now, hope we get to the even more efficient 25% sooner than later.

Paul

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Nope. Ethanol has much lower efficiency than gasoline. Or diesel for that matter. Plus the cost of converting from bio-stock means Ethanol may even have a negative efficiency rating by the time it's blended with gasoline for retail sale.