Guys,
If you have upped the performance of your Fiero (especially if you are running a supercharged swap) you need to test your fuels ethanol content. When I first switched over to E85 a few years ago, I had no idea that E85 being sold might only contain E60... I also had no idea as to why it would really matter. Well, it does and here is a quick lesson in how to test and simplified reasons letting you know when/why you should.

https://youtu.be/BKlfcpqRsaI

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84/87 NB, 3800SC, E-85, VS Cam, 2.8 Pulley, 4T65E-HD, HP Tuners, AEM Wideband, Regal GS Gauges, S-10 Brake Booster. 1/4 mile -11.85 at 114mph

What do you do with the fuel that's now been contaminated with water? Do you put it in the tank of the car?

quote Originally posted by pmbrunelle: What do you do with the fuel that's now been contaminated with water? Do you put it in the tank of the car?

The volume of water is not much and it gets absorbed by the ethanol. I mix it with the small can of e85 I use to start recreational fires in the back yard.

This Only Matters to people that think they can run E85 on cars without Flex Fuel equipment. (Some areas have E15 also made to work in Flex Fuel vehicle only.)

W/o Flex Fuel sensor(s)...
Every time you change % of Ethanol for any reason like you just drive to anyplace w/o E85 pumps and need gas then that ECM/PCM will need reprogramming to run the engine right. More so w/ DIS and related because can't even adjust Base Ignition timing like Distributor engines like HEI etc.

"E85" has less Ethanol then advertise is no surprise to many. Often same reason "Normal" pumps w/ 10% Ethanol labels are often wrong. Depending on Summer/Winter mix at the "Local" bulk fuel distributor and just where you are can change the gas formula and amount of Ethanol added to meet USEPA and states rules of gas used in an area.

Even when you buy fuel only at 1 station, the %E can and often will change. Very likely Winter "E85" fuel often needs less Ethanol so more vehicles will Start reliable in cold weather. Depending on Ethanol availability at a given time may change %E for Summer "E85" fuel or even from batch to batch delivered by local tank truck at any time of year.

So More accurate is "normal" pump saying "Up To 10% Ethanol" because many places have much less Ethanol at different times of year. E15 or E85 should be label the same but creates a huge problems for stations and 99+% of buyers that have no clue and don't care.

Ethanol is added at the "last mile" distributor then ship to your local station by tank truck because Ethanol Cannot be put thru nation wide oil/gas pipeline system. At minimum... If/When their E tanks are low, they must make sure they have enough to keep "E10" flowing out to the stations to meet EPA/state rules and if needed "F" the E15 and E85 users because was made to use in Flex Fuel equipment and the vehicles w/ it don't care.

Note that gas is same for all stations in most areas but whatever additives for cleaning at Texaco etc are added at same "Local" distributor before loading on a tank truck or even at the time of delivery for whatever brand of gas. ("Last Mile" "Local" distributor can be 50-100 miles away maybe more from your local station.)

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Yep, most people have no clue about these things but people who know about performance know about E85. There is the few percent of the population that are truly clueless. I wonder how many of them stop in time after accidentally filling up with E85 and the trims cannot possibly make up the difference. Check engine light comes on for sure - but for many - that just means get it looked some day. That would be super lean.... not good.

Thanks for all the back story info on the last mile local fuel distributors adding ethanol and additives. I was not aware of that.

Cheers!

Dime.

Seems like you could tune for E50... fill a drum half-full with some E85 (which could have not much ethanol), and then keeping adding pure premium gasoline until the ethanol is down to 50%, possibly using a flex-fuel sensor.

This way you could remove the variability from the ethanol percentage at the pump, and always have the same thing going into your car.

Maybe you could even do it in the fuel tank of the car with the fuel pump running to mix things. Fill with some E85, then top up with gasoline until the flex-fuel sensor says you're at 50%. The flex-fuel sensor doesn't even have to be connected to the ECU. It just needs to go to a gauge you can see while filling up.

[This message has been edited by pmbrunelle (edited 05-09-2020).]

quote Originally posted by pmbrunelle: Seems like you could tune for E50... fill a drum half-full with some E85 (which could have not much ethanol), and then keeping adding pure premium gasoline until the ethanol is down to 50%, possibly using a flex-fuel sensor. This way you could remove the variability from the ethanol percentage at the pump, and always have the same thing going into your car. Maybe you could even do it in the fuel tank of the car with the fuel pump running to mix things. Fill with some E85, then top up with gasoline until the flex-fuel sensor says you're at 50%. The flex-fuel sensor doesn't even have to be connected to the ECU. It just needs to go to a gauge you can see while filling up.

Once you ID the ethanol content in your 91 octane and your E85, you can do the math to determine how to get the mix you are looking for. There are even calculators on the internet you can use. Then I just pull up to the pump and pump the amount of each fuel to get the blend I am looking for. My SC 3800 needs as much ethanol as I can give it for summer racing. I have another supercharged car that does not need as much so I mix up E33 all summer long.

Cheers!

[This message has been edited by DimeMachine (edited 05-10-2020).]