E85 FlexFuel vs Regular gas calculations

[WhiteStripe]

Hey Everyone,

I live in Austin, Texas and I've had my 2011 Tahoe since this spring and over the summer I did a little experiment on MPG measurements using E85 versus regular fuel. I knew E85 was less efficient but wanted to see just how much compared to the price difference.
I ran 6 full tanks of gas for each type of fuel (in a row) over a range of mixed (city/hwy) use driving. This includes a bit of idling due to sitting in my car and remote starting the engine to cool the vehicle down (remember I said Texas and Summer).

And my results were:

E85 = 11.49 MPG
Regular = 15.47 MPG

If you use regular gas as your starting base point, e85 fuel is 25% less efficient. So, to make it worth it, the price would have to be at least 25% cheaper. For me it wasn't. As I remember, in very general terms, Regular gas was costing about $3.30/gal and E85 near my work was runnning about $3.00/gal at the same time. So, it was roughly 10% cheaper.

Therefore, I will not be using E85 gas anymore since it is not worth it, unless the price goes way down.

Anyone else have any experiences that you would like to share?.......

 

[Zed 71]

Similar calcs when I bought mine back in 2007. But you not getting very good mileage on regular. I got better when I was stock (~17 city mpgs), and getting around ~16 mpgs now with level kit and MT tires (but I have the BB tune ).

 

[StevenFromTexas]

I have had the good fortune to never accidentally purchase the watered-down, worthless, corporate welfare product called E85. Unless one likes to waste money, there is no use in purchasing the product. Indeed, E85 has the potential to kill just about every boat engine built to date, and murder almost all lawn care products like leaf blowers, chain saws, and weed wackers.

The best use for E85 would be to make politicians who support the product drink it before they vote for any more handouts for all of the parties pigging out on tax money.

 

[OHSIXX]

I also heard you have less HP with E85....did you notice less giddy up??

 

[edgaranah1]

Similar calcs when I bought mine back in 2007. But you not getting very good mileage on regular. I got better when I was stock (~17 city mpgs), and getting around ~16 mpgs now with level kit and MT tires (but I have the BB tune ).

16 mpg city? Damn I get 11-12 max.
I get 16 on highway

 

[CYKBC]

If zed is getting 17mpg city he is getting near hybrid efficiency in a non hybrid rig. Most hybrid guys are netting real world mpg around 18.

 

[Regency]

16 mpg city? Damn I get 11-12 max.
I get 16 on highway

Same must be a yukon thing

 

[Zed 71]

Is the Yukon AWD and for those of you with larger rims/tires, did you get the speedometer/odometer adjusted for the increased size?

It seemed like the Tahoes with the 4.10s were getting better mileage. The thought was the truck could get up to speed with less effort and it seemed like V4 mode would kick in more often. Back then I only had a K&N intake and Magnaflow exhaust.

Now with all the mods, I get ~16 mpgs in city or highway.

 

[BP RETIRED]

no calculations here....but last month I tried E85 for the thrid time or so and few miles later got a CEL light. Code said P1175. Which meant a side of the engine was running lean. Shorlty there after I then got another CEL code P0302. This said cylinder 2 misfire. I did not think it was the e85 so I started to trouble shoot it. Cleaned the MAF sensor, which was very dirty. Changed the coil, wire, and spark plug on cylinder 2. Reset the CEL and boom...the light comes back on. Same codes. Now im starting to think it the E85, but then I figured that my Tahoe is a FFV and either I got bad E85 or some type of interior engine problem. I ran the tank of gas with the CEL on and then placed regular gasoline in the Tahoe. I think I just put in the mid grade. A few miles down the road the CEL light goes off. I guess Im not running E85 any time soon.

 

[jdpber]

e85 is junk...... dad got a 3gal of it by accident for the weed eater.. it fried a $250 echo professional weed eater..

keep your boat far far far far away from this water crap.. it is horrid.. i pay extra for NO ethanol fuel for the boat.. the ethanol fuel runs like crap, even with octane booster..