Monday, June 16, 2008

Just how much ethanol is in E85 this time of year?

Commenter Alcohol said that E85 is actually 83% ethanol this time of year.

I beg to disagree.

June is a "2" month, 2 being 74% ethanol, minimum.

I need to find a hydrometer that can measure the ethanol content at the pump. This guessing business is nuts.


Anonymous said...

I see your link Buzz- I use the same reference manual to set blends- note June is 2/1 thus is optional for the station owner what he sells. The blend actually starts to change the month prior at the blend rack so that the station owner has in his tank for sale the correct product per the chart in the month sold. At $1.40/gal difference between ethanol w/ credit and gasoline it is unlikely the station owner is going to have a more costly product than required by federal ASTM standards.
While it is possible he may be carrying over spring product or a mix of spring/summer in the event of low sales- it is unlikely station owners purchased E76 since mid-May. Racks in Wisconsin (even more restrictive zone were posting E80 during May.

Buzz- in the back of the Federal Handbook your numbers came from is a test procedure for determining % ethanol via phase separation. While this test is not high precision it is easy and all you need is a graduated cylinder and an accurate pipette for water.

The same method can be used to determine final ethanol content--
in a 100ml sample of e10 if you add 10 ml of water and shake very well this will yield 17 ml of phase separation. E20 would be 24 ml of separation, E30 would be approx 31 ml. The reason the E85 test in the handbook does an approx 50% water inclusion is that 10 ml will not drive a phase separation in high levels of alcohol.

Another thing confusing about the handbook is that in a different chart area it spells out min-max hydrocarbon levels for each season class.


buzzcut said...

Have you ever gone in and asked about the ethanol content?

Would a clerk know such a thing?

Could you call the county weights and measures department to find out?

There has got to be a better way of figuring this out!

Anonymous said...

The store clerk may not know but knows who sees the load documents as they come in- see if they will give you the contact info.