I noticed the other day while gassing up my cap says E85, I was just wondering if anyone was running it. Being that my 6.8 dually is a 3rd/4th vehicle, and I don't have stations near me, I probably wouldn't run it all the time, but on trips if it's available and that much cheaper than regular (60 cents less in my area) I thought I may give it a try. I've never had a vehicle that can run it lol, so I really don't know squat about it

 

It’s cheaper but I think it uses a lot more (aka your gas mileage on that truck will be abysmal with it). I wouldn’t want to know what kind of mileage a 6.8 dually would get towing anything on e85.

Some vehicles are rated to run it but I’ve still heard people saying it’s not so great to run.

definitely do some research before doing it.

 

When I had my 2016 the price vs mileage was about a wash compared to regular. Tried it in my 2023 7.3 once and it seemed better than the 6.2 but I don’t recall the numbers, just that it seems better than my 2016.

 

In my last truck, running e85 would net 20+ hp. It runs cooler and generally has a higher octane. You might find you tow better with it, but everyone’s right… the mileage takes a hit. Depending on the price difference, it can be cheaper or pricier per mile.

You may notice it take a second or two longer to start, but with my truck, it ran better. It was a Chevy with 4cyl mode. I would notice it would be able to run longer in 4cyl and wouldn’t switch back and forth as often.

 

Thanks folks, it's intriguing so I will definitely look into it some more. I may give it a shot sometime on an empty trip, or short trip with the camper in tow. We're planning on running empty to Ocean City this summer so that may be a good time to try it out.

 

I'm curious as to how bad it could really be towing, I'm figuring this truck to only get 5-6mpg towing anyhow, could it really be significantly worse than that lol. I borrowed our work truck (17 GMC 2500 with the gas 6.0) back in 19 when we bought the camper and that got 4.5mpg coming across PA with the empty 10k camper.

 

E85 is a mixture of ethanol and gasoline, typically consisting of 51-83% ethanol, with the remaining percentage being gasoline. Ethanol is hygroscopic, meaning it attracts and absorbs moisture from the air, so E85 can have a higher water content than regular gasoline, especially if exposed to high humidity or if it's stored improperly. STAY AWAY FROM E85 - TERRIBLE STUFF.

 

Interesting. We used to poor a bottle of alcohol in our tanks to removed the water from the gas tank. I would think ethanol would be a great tank cleaner. Also as far 20HP increase? I would like to see the science behind that.

 

You put E85 in a 7.3? AFAIK the 7.3 is not flex fuel, so not E85 compatible. My cap reads E0-E15. I would double check yours before adding E85 again or you could cause some damage by running too lean. If that was a typo and you have a 6.8 though I believe those are flex fuel.

 

I personally do not race any type of vehicle but I have heard it is better to run than other pump gas for racing purposes for higher horsepower output. E85 is just not for me as far as daily driving is concerned. And as I am sure that everyone is aware of by now, NEVER run any type of ethanol gas in any carburetor engine.

 

E85 is about 105 octane equivalent and ethanol's higher volatility gives better mixing and better air charge cooling. All this together means you can run significantly more timing than standard gas. I don't know about andrew's last truck but I was surprised to see that my 24 7.3 only runs 10 degrees of timing advance at WOT unloaded (via banks idash), but runs in the 30's at cruise. It wouldn't be a flat 20hp across the board but there's a lot of room for timing advance and increased power at higher loads with the right fuel.

The way flex fuel works is the difference between the "anes" like methane, ethane, butane, hexane, octane and the "ols" like methanol, ethanol, butanol, hexanol, octanol is the inclusion of an Oxygen atom in the carbon chains for the alcohols. Octane is C8H18 and Octanol is C8H17OH so there's still 18 Hydrogens but 1 of them has an Oxygen bonded to it. Ethane is C2H6 while Ethanol is C2H5OH. It's the same for all of them (The prefix meth, eth, but, oct and so on tells you how many Carbon atoms there are; 1, 2, 4, 6, 8 respectively just like the names of polygons). The flex fuel sensor is able to read this Oxygen atom and so determine how much of the fuel is an "ols" vs an "anes" and adjust how much fuel to inject and how much timing to add according to the ratio. Off the top of my head going from 100% gas to 100% alcohol I think requires about 25% more fuel (but it's definitely significantly more even if that number isn't accurate) which is why you can go too lean and cause damage putting E85 in a non-flex-fuel vehicle.

The addition of the Oxygen molecule is also why water is able to bond with alcohols and that's why "water remover" aka "dry gas" additives are really just alcohol. They don't remove anything, they just act like glue between water and gas so they can mix instead of puddling at the bottom of the tank. As long as it's mixed well water in the combustion chamber won't hurt anything, in fact a lot of performance builds inject water directly to the intake charge on purpose. Too much of it though, especially without a flex fuel sensor gives you the same running lean problem, as well as lubrication reduction of pumps and injectors.

 

I used to run E85, one tank a year, when I had a truck designed for it. The MPG hit was close to 30% and never came close to being a cost savings, but I did it to clean things up internally. Don't know if it made a difference but it didn't seem to hurt anything except my wallet. I haven't run any E85 after seeing the special maintenance schedule needed if you run E85.

 

What is the special maintenance schedule. Nothing in my owners manual about that.

 

We have several ethonal free options near me. I use that for all gas engines if and when possible, including our Armada. I use it exclusively for lawn mowers, trimmers, blowers, etc.

 

My mistake, E15, 85% gas not E85, 15% gas Good catch!