Started using E85 today ... it'll be interesting to see mileage results!

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

BG1988

Full Access Member
Joined
Nov 14, 2018
Posts
2,925
Reaction score
1,329
Is this on E85?

The OP drives a 2014 Yukon XL Denali and wondering what kind of mileage to expect on E85, not a hybrid on 91 or 93, but thanks for sharing...... lol

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
E30 will get you optimal fuel MPG e85 will lower it

E30 = 94 octane fuel
 
Joined
Apr 11, 2018
Posts
6,282
Reaction score
12,258
Location
St. Louis
E30 will get you optimal fuel MPG e85 will lower it

E30 = 94 octane fuel
Yup it sure will, but it costs more than E85 and just a tad cheaper than 93. You won't get the power increase the higher octane E85 will give.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
 

homesick

Full Access Member
Joined
Sep 19, 2018
Posts
525
Reaction score
831
Yes I'm expecting to get lower mileage, however my understanding is that you can get more power from it.

I don't know who's right in this argument, but less energy isn't going to get you more power.

About all I know about corn gas is that it's corrosive, rots rubber, and raises food costs.

joe
 
Last edited:
Joined
Apr 11, 2018
Posts
6,282
Reaction score
12,258
Location
St. Louis
It has less energy, that's why it uses more fuel and you get less mileage. You get more power from it because it is really high octane, about 105 (vs 93 premium) and the computer detects the alcohol content and runs higher spark tables and gets more power out of the engine. Basically like race gas

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
 
OP
OP
fastscirocco

fastscirocco

Member
Joined
Feb 21, 2019
Posts
62
Reaction score
60
My 2012 Denali XL gets about 9-10 mpg in town and 13-14 highway on E85. On 93 octane it gets 12-13 in town and 16-17 highway. My AFM (V4 mode) is tuned off, and A/C is usually on most of the time.

Factory says only a 7hp (403 vs 410) peak when on E85, but that's just at peak. On E85 there is more power throughout the rpm range and "under the curve". You will notice a difference from right off idle and at part throttle.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18



Thanks for the info!

So far my fuel consumption numbers are mirroring yours; ~ 10 mpg in the city and ~16 - 18 mpg on the highway on E85.
I filled up yesterday at $2.04 a gallon - it was a considerable savings of premium's $3.24.
Today gas prices have risen considerably, the same station now sells E85 for $2.39 and premium for $3.59.

I'm assuming 30% less mileage from E85 and do a simple calculation to determine which is the better deal when I fill up.
premium gas price * .70 and compare that to E85 price.

$3.59 * .70 = $2.51 > $2.39 for E85 - better deal to purchase E85.
 

Larryjb

Full Access Member
Joined
Jul 21, 2016
Posts
1,140
Reaction score
1,045
I don't know who's right in this argument, but less energy isn't going to get you more power.

About all I know about corn gas is that it's corrosive, rots rubber, and raises food costs.

joe

I was wrong earlier in my post about power. I forgot that power is simply how fast energy is used. So, even though there may be less energy per gallon in E85, it uses the E85 slightly faster, which leads to slightly more power.
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,100
Reaction score
25,029
Location
Treasure Coast, Florida
About all I know about corn gas is that it's corrosive, rots rubber, and raises food costs.

I used to agree with you Joe, now I'm not so sure about all that. Our farmers have increased the yield of an acre of corn every year and in 2017 an acre of corn yielded an astounding 176.6 bushes. Each bushel has 2.87 gallons of ethanol in it but the leftover has many other uses.

I figured I could supply my truck with 1000 gallons of E85 and would use just 1.6 acres of corn per year and 200 gallons of gasoline to run E85 @ 80% alcohol.
 
Top