Do not buy E85 !

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That is, do not buy E85 for your FlexFuel vehicle, unless you have a nearby steady supply of E85 to feed your new habit. Of course, I'm speaking strictly for myself and my '14 F150 with 3.7L V6. I tried E85 as an experiment...a goof maybe...but the joke was on me. My truck absolutely loves it, and runs with a whole different personality. Throttle response is up, trans shifts quicker...it's truly like a different vehicle. Even going back to 93 octane gasoline is not enough to make the same difference. My problem, in a nutshell, is that the nearest station I can get it is 1.5 hrs away. Fortunately, my work takes me past it often...but not often enough.Now, admittedly I am running a 5Star 87 octane performance tune, so that may allow the truck to better take advantage of these benefits. Yes, I lose a hand calculated 3mpg ( I calculate every tank of every type of fuel), however, when comparing to the next best option of 93 octane, the price break is $1 a gallon ($2.03 E85 vs $3.09 for 93) I'll take that loss. All political aspects/opinions aside and speaking strictly from a performance standpoint, I wish more stations carried it....moral of the story don't try it unless you can support the habit. Drive safe !
 
Anyway to get multiple tunes and switch back and forth?

I know a 93 octane tune is significantly better than an 87 octane tune.

and e85 is even higher octane.
 
I could buy other tunes, and re-flash each time...but seriously, it's more than enough of a difference for me...just wish I could buy it closer to home.
 
I toyed around with the idea of buying something flexfuel, but it seemed moot since the e85 here is rarely more than 20% less than 87, and I was told to expect about a 15-20% loss in mileage.
 
I know the energy content of E85 is supposed to be less, but it's supposed to be way more efficient when it can advance the timing. It's almost like 100 octane racing fuel.

The main issue I've heard with regards to performance boosts using E85 is that there isn't a terribly consistent proportion of gasoline. The more there is, the lower the performance benefit. And when you're doing comparisons it's really tough when there might be a difference in gasoline content.
 
E85 can be anything from 51% to 83% ethanol. Worthless to me. If it's so good, why do my tax dollars still subsidize it?
mad.gif
 
Originally Posted By: Merkava_4
Originally Posted By: Rand
and e85 is even higher octane.

e85 is higher octane than 93 ?

Yes. E85 is typically 100-105 octane.
 
Just filled up the Tundra with E85 on the PA Turnpike. An experiment.

Truck runs fine, it seems a bit more responsive. MPG is down a bit according to the trip computer.

But I'm certain that my experiment is costing me $$. The price of E85 here was $2.67. Same as regular. (Turnpike gouging) so, with the MPG hit, the E85 is at least as expensive as premium, which the truck doesn't require.

Further, I had to go inside and pre pay. I had to tell them, more than once, that my truck was flex fuel, before they would turn on the pump.

Too many morons had filled up regular cars from the big yellow pump, with the yellow nozzle and warning labels....
 
Maybe you purchase and use a storage tank so that you have a supply at the house or on back of the truck. Then you can refill it when your travels take you there for work
 
I suppose the one thing about these flex fuel vehicles is that they're designed to actually take advantage of higher octane rated fuels. Has anyone here tried something like 100 octane street legal race gas?
 
My 04 Explorer is flex fuel and I have run the E85 at times and noticed it will get up and go a little quicker with it but the gas mileage does take a hit. My owners manual states if I run the E85 all the time to change the oil at 3000 miles instead of 5000 miles, also the plugs have to be changed sooner. I also found out when I first bought it that if I was running 87 octane and topped off with the E85 there was a good chance of tripping a check engine light so it was recommended by the dealership to add at least a half tank or more when going from one fuel to the other.
 
Have topped off from 3/4 tank gas...to completely empty(fuel light on) and fill up with E85. No issues with the changeover, or check engine lights. I'll have to read the manual closely, but don't remember any stipulations about OCI or spark plug changes. Simply put , the more alcohol the better it runs. Yes, you will get less mpg, but as stated before, the price break for me,even over regular(87) is nearly $.40 per gallon, $1 vs premium (93). I've read of similar results , especially in boosted applications, it was merely an experiment on my behalf to confirm/deny the stated results (confirmed in my opinion)and share my results. I will now test a little further...allow me to explain. I'm curious if it's strictly due to increased octane or is there more to it ?? FlexFuel vehicles detect a change in exhaust oxygen content via the oxygen sensors and increase or decrease the injector pulse width(time)to inject more fuel for a given pulse (simplified version) Does it run cooler temps in the chamber, resulting in denser charge? Are there other components to it in addition to octane that result in increased performance ? When I have run couple tanks of just gasoline , I am going to run couple tanks of 93 octane, with an octane booster added to hopefully account for the increased octane only...and report back my findings. Totally unscientific , as I'm simply using my butt dyno and personal opinion...but I'll enjoy it...I hope you will too.
 
I've heard that since more fuel needs to be dumped in with E85, the tendency is to cool the mixture, which can make it slightly more efficient with respect to the actual energy content of the fuel.
 
Originally Posted By: y_p_w
I've heard that since more fuel needs to be dumped in with E85, the tendency is to cool the mixture, which can make it slightly more efficient with respect to the actual energy content of the fuel.


The extra fuel should cool the incoming air somewhat (unless it's a GDI) which will increase volumetric efficiency a bit but the extra fuel also takes up some volume that could be used by extra air decreasing volumetric efficiency somewhat.

In a boosted engine where boost is limited by detonation that's less of an issue since the extra octane of the E85 means you can increase boost.

There's less energy content in the fuel though so fuel mileage is going to go down no matter what (unless you drive more slowly).
 
We may remmember that alcohol has oxigen atoms in its molecule, decreasing a lot the need for the oxigen in the air for proper combustion. So, Even the bigger air to fuel ratio, helps on the oxigen content.
 
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