E85 confusion

[Kendar]

So I was messing around on the Ford website this morning, and just for grins I did a vehicle comparison of the Expedition (which we're getting ready to buy), and the Chevy Suburban. This is what was listed about the Chevy engine....

Flexible Fuel 5.3-Liter Vortec, V8, 16-Valve, OHV, SEFI Engine; Front Mounted With Horsepower Of 320@5200, Torque Of 340@4200, Cast Iron Block and Alloy Cylinder Heads; Runs On Ethanol/Gas Mixture With Up To 85 Percent Ethanol (Primary Fuel Economy With 100% Gasoline Is 15-City, 21-Highway and 17-Combined; Secondary Fuel Economy With 85% Ethanol Is 11-City, 15-Highway and 13-Combined) (Standard)

Unless I haven't had enough coffee, this looks like the gas mileage is worse with the E85. Am I reading this wrong?

[CoPoGT]

No you read it right. They get worse gas mileage on the E85. A friend of mine has an F150 that can run both. He figured about a 15% loss in gas mileage running the E85. The gas is cheaper so in the long run you will see about a 2 to 3 dollar return per tank running the E85 factoring in the difference in price and mileage per gallon

[mr deeds]

CoPoGT has it right. There is less energy in a gallon of E85 than a gallon of striaght gasoline, so the miles per gallon of E85 is less.

[lostsohcs]

Originally Posted by Kendar

So I was messing around on the Ford website this morning, and just for grins I did a vehicle comparison of the Expedition (which we're getting ready to buy), and the Chevy Suburban. This is what was listed about the Chevy engine....

Flexible Fuel 5.3-Liter Vortec, V8, 16-Valve, OHV, SEFI Engine; Front Mounted With Horsepower Of 320@5200, Torque Of 340@4200, Cast Iron Block and Alloy Cylinder Heads; Runs On Ethanol/Gas Mixture With Up To 85 Percent Ethanol (Primary Fuel Economy With 100% Gasoline Is 15-City, 21-Highway and 17-Combined; Secondary Fuel Economy With 85% Ethanol Is 11-City, 15-Highway and 13-Combined) (Standard)

Unless I haven't had enough coffee, this looks like the gas mileage is worse with the E85. Am I reading this wrong?

Yep, you do get worse gas mileage with E85 unless you tune to use only it. My wife has a flexfuel van and it averages about 10% lower fuel mileage with E85. There is less energy per unit in alchohol than gas so without adjusting timing to take advantage of the 105 octane of E85 you use more. There are a couple places that will tune Ford vehicles for use on E85 and I bet that they use settings that would cause dangerous detonation on Gas to raise the mileage.

[Kendar]

Originally Posted by lostsohcs

Yep, you do get worse gas mileage with E85 unless you tune to use only it. My wife has a flexfuel van and it averages about 10% lower fuel mileage with E85. There is less energy per unit in alchohol than gas so without adjusting timing to take advantage of the 105 octane of E85 you use more. There are a couple places that will tune Ford vehicles for use on E85 and I bet that they use settings that would cause dangerous detonation on Gas to raise the mileage.

Huh. As always, you guys are a wealth of good information. I never realized the octane was that high. Isn't 105 pretty close to the octane rating of race fuel?
It's kind of a moot point for me right now, because there's only one station within 20 miles of my house that sells it, and that place is in the total opposite direction of anywhere I would go. I just like to be informed. Thanks fellas.

[bobbys97R]

all e-85 is a renewable power source they make carbs for it nowas well

[WorkingClassSkin]

Cocaine is a renewable power source, too. Doesn't make it a good idea, though.

[hotwheels]

lmao............

[Gtconv91]

as said above.. E85 makes less energy then 87 octane gasoline... so you have to use more E85 compared to gasoline... you would have to buy kits to convert a efi to flex fuel and re jet a carb and in my opinion its a hellova lot cheaper then sunoco/vp and you can have 12:1 compression on pump gas!!!

[J&SPolishing]

To make a Mustang a flex fuel vehicle is simple, done it a couple time. Plus boosted cars love E-85. On a EEC-IV just use a Diablo flip chip, one tune for pump gas, and one tune for E-85. Just make sure you have enough injector for E-85 because it uses about 30% more fuel under power. On a EEC-V vehicle, you can use a Predator just have a couple tunes loaded for pump gas and E-85. We have never had a fuel pump failure or fuel line failure using E-85. Some people say because E-85 is corrosive it will eat the pump or fuel line. Even Walbro says their pump is not E-85 compatable, but we have beem doing it for over a year without a failure.