Finally got curious and spent ~ $30.00 to test out the Ethanol content of my local gas station.
1. Shell 91 Octane-'Nitrogen Enriched' gas. (Highest Octane you can get in Colorado).
2. Pump states " Up to 10 percent Ethanol".
Test results: E8
Modified B3601 to Read: 14.2262
B3618: 1:16 EQ..~ 12.25 AFR
From left to right (in photo).
1. Fuel Dispenser Bottle. Allows you to safely pour gasoline from approved container into an easily pour-able bottle.
2. Fuel Tester Stand. Here you mix a precise amount of water ( 1 teaspoon) into container, followed by ~ 1 Tablespoon of fuel.
3. "Quick Check Solution'. Detects alcohol. Colors alcohol blue.
4. Safety gloves.
So you put a small rubber end (supplied) into the Fuel Tester and shake vigorously. You let it stand for about 30 minutes. You then read Ethanol content on a scale on the front of the Dispenser.
Comments: Technically you could devise a method to do this at home using your own supplies. The scale was incremented every 5% so it was a little hard to read.
Tune-wise I did a CALC.VE using 14.68 as my value in B3601 (using same fuel as test). I then adjusted B3601 to 14.22. My Trims went from -1.3 to -4.4%. Overall then my MAF & CALC.VE lowered by the same 3% to maintain the same LTFT ratio.
Overall an interesting test. While as Tuners we all agree AFR is not the value we should tune by, you still have to use it in B3601. I.E., you still have to understand the relationship between Lambda, EQ, and AFR.