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School me on E85

DFW Rusty

DFW Rusty

Well-known member
Joined
May 21, 2020
Member Number
898
Messages
395
I just bought a brand new f150 w/ 5.0 v8 that says it's a flex fuel. I have been googling e85 and supposedly it's safe in a d/d, not good for anything that sits for much time at all. My truck never sits more than maybe a day or so on the weekend (at the absolute most 1 day). I burn about 2 tanks of gas a week, and with gas prices the e85 is looking better each time I fill up!

My wife has been running e85 in her car for the last 2 years and her car has been problem free so far.... she drives the exact same miles as I do for work.

From google sources what I have found-
  • Supposedly it helps clean the internals on your engine and fuel system.
  • is harder on seals if left sitting for long periods of time.
  • e85 has a very short shelf life.
 
Everything you found is mostly true.
I would advise you to check your mileage by hand and keep a record of it vs regular fuel. The MPG and what you paid per gallon. Some platforms take a big mileage hit when running corn liquor, some don’t. Make sure it’s not costing you more money in the long run.
 
The shit is fucking horrible but it's here to stay i guess.

It'll be fine in your F-150 but don't put it into an ATV or any small engine for that matter because it deteriorates really quick.
 
Run it if it pencils out. I run it in my Shelby in the summer. 22 mpg on gas, 15 mpg on E85. Tests out at about E70 here.
 
IowaOffRoad said:
Everything you found is mostly true.
I would advise you to check your mileage by hand and keep a record of it vs regular fuel. The MPG and what you paid per gallon. Some platforms take a big mileage hit when running corn liquor, some don’t. Make sure it’s not costing you more money in the long run.
Click to expand...
^ This. It also runs much cooler and those that like to make a lot of boost like it.
 
I tried going back to 87 in my Chevy. Hard starts and I was about to start digging into a fuel issue. Tried a couple tanks of 92 and have been problem free since (been 3 weeks). $4.15 a gallon hurts. I even swapped to the highest grade NGK plugs and wires I could find with no change.

I’m pretty sure E85 would kill my truck. But the price would be awesome. Pretty sure a ton of people run that stuff out west. Noticed it’s everywhere out there and that’s usually the posted price on the signs out front. Most of our pumps don’t offer anything less than 87.
 
I've run E85 on road trips a few times where I could back to back tankfuls to see if there was much difference.

In last gen Chevy Impala, there was maybe 1 mpg drop if that. Not the drastic drop I had heard of.
 
FleshEater said:
I tried going back to 87 in my Chevy. Hard starts and I was about to start digging into a fuel issue. Tried a couple tanks of 92 and have been problem free since (been 3 weeks). $4.15 a gallon hurts. I even swapped to the highest grade NGK plugs and wires I could find with no change.

I’m pretty sure E85 would kill my truck. But the price would be awesome. Pretty sure a ton of people run that stuff out west. Noticed it’s everywhere out there and that’s usually the posted price on the signs out front. Most of our pumps don’t offer anything less than 87.
Click to expand...
E means Ethanol percentage. Ethanol also has less energy per unit, so fuel mileage often goes down. Frequently end up matching or going up in dollars per mile.

85 octane is available in higher elevation areas.
 
I don't see much of an MPG difference in my wife's escalade so will run it if we see it. Won't go out of my way for it though.

Months ago during the manufactured panic-buy gas shortage e85 was never out of stock so that was nice.
 
Last time I checked the cost per gallon difference didn't make up for the loss of fuel economy.

That was a few years ago, However.
 
You have to use more e85 than gasoline for the same power, I don't see how that would pencil out for street driving.

With E85 you can run more timing in a performance engine. People are running E85 with a tune and headers on mustang GT's and putting over 500 hp to the ground. The Mustang coyote 5.0 is ~12:1 compression, so it likes the higher octane and more timing. I wish we had E85 here, I'd like to try it in my 11.5:1 SBC with bigger jets in carb and more timing. I can only get 91 or 108 octane from a pump here. I'm cheap so I run 91 octane with less timing most of the time.
 
Thumping said:
^ This. It also runs much cooler and those that like to make a lot of boost like it.
Click to expand...
E85 is in the 100-105 octane range, so it works well with high boost or compression.

In the 7.3 Ford thread there is a video of a stock block, cam, heads, engine with 8 psi boost, 93 octane gasoline making 800hp. Running E85 at 20 psi boost made 1015hp.
 
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E85 is basically cheap race gas. Even na picks up some low end power from it. Boost is where it makes its living though. High compression makes it shine as well, it works great up to around 14:1.
 
I just converted my Toyota 86 to flex fuel. I few things to note.

-Not all E85 is 85% ethanol. I have seen 70% and 80% around me (I have access to the sensor data stream)

-Mo Powa! Tuned for 105 octane in a 12.7:1 compression engine I was able to gain 35+ HP/TQ from an engine that puts out 200HP

-Cold morning hard starts. I just about gave up getting my car started the other morning at 40*F on 80% ethanol. It did start, but it was not happy about it. I have switched back to gasoline for the winter.

-Reduced fuel mileage. I was getting 33MPG cruising on the interstate on gasoline, that was reduced to 22MPG on E85
 
The gas station just down the street from me is $2.44 per gal of E85 and $2.89 for regular gas. That equates to about a $15 savings per week give or take assuming that my mpg wont change much.
 
JohnnyJ said:
I've run E85 on road trips a few times where I could back to back tankfuls to see if there was much difference.

In last gen Chevy Impala, there was maybe 1 mpg drop if that. Not the drastic drop I had heard of.
Click to expand...
I bet in town you would see a greater drop in mpgs
 
DFW Rusty said:
The gas station just down the street from me is $2.44 per gal of E85 and $2.89 for regular gas. That equates to about a $15 savings per week give or take assuming that my mpg wont change much.
Click to expand...
OK, WHY would you think that??? NOBODY, and I mean not even Ford, says the mileage won't change much/

If you believe the chart, you MAY save $50 A YEAR, and spend more time at your local gas station. ( I hate getting gas, I want as long between fill ups as possible, myself)
Capture3.JPG


Fuel Economy of New Flex-fuel Vehicles

Fuel economy of the . 1984 to present Buyer's Guide to Fuel Efficient Cars and Trucks. Estimates of gas mileage, greenhouse gas emissions, safety ratings, and air pollution ratings for new and used cars and trucks.
www.fueleconomy.gov www.fueleconomy.gov
 
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My Tahoe lost 17% in MPG for the 12% reduction in fill up costs. Not worth it, and it felt like it lost power most of the time
 
The hit in mileage is one of the reasons I think E85 is better as a budget performance fuel than a money saver for a commuter.

HOWEVER, I do think that if you built a platform to take full advantage of the benefits of E85, you could make up some of the MPG and gain some real horsepower. The disadvantage of doing this is not being able to switch back very easily. I think building a strictly E85 vehicle for a summer toy when the alcohol content is somewhat stable in pump fuel, in an area that offers it in every town, would make for a cool project. Think 13:1 big block that knocks down mileage in the low teens and makes 550rwhp. I think something like that is doable, but you couldn't put 91 in it in a pinch at that point.
 
grumpy356 said:
OK, WHY would you think that??? NOBODY, and I mean not even Ford, says the mileage won't change much/

If you believe the chart, you MAY save $50 A YEAR, and spend more time at your local gas station. ( I hate getting gas, I want as long between fill ups as possible, myself)
Capture3.JPG


Fuel Economy of New Flex-fuel Vehicles

Fuel economy of the . 1984 to present Buyer's Guide to Fuel Efficient Cars and Trucks. Estimates of gas mileage, greenhouse gas emissions, safety ratings, and air pollution ratings for new and used cars and trucks.
www.fueleconomy.gov www.fueleconomy.gov
Click to expand...
I never said "I think it wont drop", I just said assuming.... I already stated, I have no frickin clue about e85... I'ver never been a motorhead type... All my crawlers have been slow and low hp. All I've ever known about fuel is that 91 octane makes my CJ5 spark knock...lol... Shit, I give the o'l gas can a sniff and if it smells like fuel it goes down the fill.
 
I filled up yesterday with E85 and so far I put 88 miles on the truck so far and I'm averaging 16.7 mpg running my normal route. With regular I was averaging 18.9-19.4 mpg.

Also gas was more than I previously posted. E85 was 2.66 and regular was 3.10. :shaking:
 
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