Quick E85 question

[Biggus Dickus]

A station not to far from me (Pilot) started carrying E85. My car isn’t tuned for it yet but in the future I’m going to have a flex fuel tune. I only run 93 in my car but it’s approaching 3.00 a gallon here and E85 is 1.92. Is it okay if I run it without the tune? I realize minimal performance benefits will be realized until it’s tuned. Wanted to make sure the factory calibration will make the adjustments.

AED - flex or race - if your E85 is reliably 85% EtOH (like it is in southern CA) go race (dedicated E85).

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[Biggus Dickus]

You can’t do this, the new PCMs log everything.

Yes you can - you simply must do as this guy does with your service advisor:

 

[Decible]

Yes you can - you simply must do as this guy does with your service advisor:

Lmfao!!!!

 

[Zooks527]

I did the math some years ago on my flex fuel truck. It fell between 27 - 31% less. So if you get 330 miles for 16 gallons you’d get 231 on E85. When I’m in town it’s 200 miles a week or I fill up every 7 days or 4x a month 93. 93 is 2.68 here and E85 is 1.93. 42.88 to fill up with 93; 30.88 to fill up with E85. I’d still have to fill up 4x a month. So you would save 20 - 50 a month in my case.

So, using your numbers above:

16 gal 93 = 330 miles, therefore (330/16) = 20.63 mpg.​

20.63 mpg @ $2.68/gal = ($2.68/20.63) = $0.130 / mile​

​

16 gal E85 = 231 miles, therefore 231/16 = 14.44 mpg.​

14.44 mph @ $1.93/gal = ($1.93/14.44) = $0.134/mile​

100 miles on 93 octane costs $13.00. 100 miles on E85 costs $13.40. It costs you 3% more to use E85 due to the lower energy density.

Your math above fails because you're assuming the tank is empty when you fill it instead of being partially full at different levels in both cases. With 200 miles per week, you'll be putting in 9.7 gallons of 93 octane ($26.00) versus 13.9 gallons of E85 ($26.83).

Decisions like these are why Mrs. McGillicutty spent so much time going over the homework assignments in algebra class.

 

[Dave2013M3]

A station not to far from me (Pilot) started carrying E85. My car isn’t tuned for it yet but in the future I’m going to have a flex fuel tune. I only run 93 in my car but it’s approaching 3.00 a gallon here and E85 is 1.92. Is it okay if I run it without the tune? I realize minimal performance benefits will be realized until it’s tuned. Wanted to make sure the factory calibration will make the adjustments.

You can get away with probably up to E30 in the car. Which is about 4 gallons of E85 if its a full E85. In Georgia you may not get full E85. Here in Cali we get the real deal actually a lot of stations test out to E87. I run 2 gallons of E85 and 2 gallons of VP101 Street Blaze to almost 94 octane here in Cali with the OEM tune and now the Ford Racing Power kit tune.

 

[Decible]

So, using your numbers above:

16 gal 93 = 330 miles, therefore (330/16) = 20.63 mpg.​

20.63 mpg @ $2.68/gal = ($2.68/20.63) = $0.130 / mile​

​

16 gal E85 = 231 miles, therefore 231/16 = 14.44 mpg.​

14.44 mph @ $1.93/gal = ($1.93/14.44) = $0.134/mile​

100 miles on 93 octane costs $13.00. 100 miles on E85 costs $13.40. It costs you 3% more to use E85 due to the lower energy density.

Your math above fails because you're assuming the tank is empty when you fill it instead of being partially full at different levels in both cases. With 200 miles per week, you'll be putting in 9.7 gallons of 93 octane ($26.00) versus 13.9 gallons of E85 ($26.83).

Decisions like these are why Mrs. McGillicutty spent so much time going over the homework assignments in algebra class.

I’m not filling up every week on 93. I was pointing out I fill up 4x a month on either fuel and I usually fill up with about 50 to 60 miles in the tank. It’s about 40 every time I fill up. I wasn’t breaking it down cost per mile. I was using the math to show what it would roughly save me a month. Marginal at best because I’m certain with an E85 tune I wouldn’t be on cruise control nearly as much. No matter which was you slice it fuel consumption is 25 -30% more on E85

 

[blue5.slow]

No need for a flex fuel sensor, I just slapped a tune from LUND on my 19 and fill up with E85.

15-17 do need bigger injectors I believe since there's no DI

15-17 can handle e85 on stock injectors

 

[vanquishvzla]

15-17 can handle e85 on stock injectors

only if you are running the stock IM... if you go +18 or something aftermarket, you need at least 47 lb injectors in order to run e85

my car is getting 200 mi range full tank with the e85, but i don't drive the car daily

 

[blue5.slow]

only if you are running the stock IM... if you go +18 or something aftermarket, you need at least 47 lb injectors in order to run e85

my car is getting 200 mi range full tank with the e85, but i don't drive the car daily

Not too bad of a mileage drop. I did some research and switching from premium gas to e85 on a GT will save you about 30 cents per mile at the current prices. Not bad at all

 

[wazslow]

Not too bad of a mileage drop. I did some research and switching from premium gas to e85 on a GT will save you about 30 cents per mile at the current prices. Not bad at all

Your numbers sound way off. It shouldn't even cost you 30 cents a mile on 93 octane.
Example...
1 gal of 93 octane is $3.00. Your car gets 18 mpg. $3.00/18 miles = $.16666

 

[Twenty4/7]

on e85 the extra mid range power makes me want to accelerate harder cruising around day to day. on 93 i dont bother. the car drinks e85 like no ones business driving it like that haha.

 

[blue5.slow]

Your numbers sound way off. It shouldn't even cost you 30 cents a mile on 93 octane.
Example...
1 gal of 93 octane is $3.00. Your car gets 18 mpg. $3.00/18 miles = $.16666

You are right I miscalculated. With my local prices, it is 2.3 cents per mile cheaper to run e85 than 93. My average mileage is around 12.5 mpg. Here, 93 is $3.10 and e85 is $2.07.

 

[VIPR01]

E85 is a wash when it comes to gas mileage, this is the wrong car if your concerned about gas mileage. But then again, in a few years it won’t matter.

 

[Copperhead73]

E85 is much cheaper than race gas. That is where it shines. I get ~220 miles to a tank of E85...ours is closer to E80 though.

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