Mpg e85 vs gas

[swathdiver]

How many of the original participants of this thread are still with us?

There was quite a bit of misinformation in this thread with regards to E85. E85 is a cleaner burning fuel that allows the engine to make more horsepower. The GMT900s have different fuel maps for it.

The ultimate measure of a fuel's efficiency is how much does it cost to drive per mile. For example, using the highway mileage in post #6 above, it costs $.13 cents a mile to drive using 87 and it costs $.12 a mile for E85. Clearly, in this example, E85 is less expensive fuel to use.

The ability to use E85 exclusively on a cross country trip is highly suspect though. For one, the vehicle's range is less and the stations offering E85 can be quite sparse in many areas of our nation.

The fella who authored post #5 reveals what those who record their mileage have long known, that all fuels are not the same, either by octane or brand. I can always count on Shell's gasoline to lose 2 miles per gallon with their 93 octane offering compared with Sunoco's. We get 1-2 mpg better than Sunoco's on Mobil's 93 octane.

 

[HiHoeSilver]

How many of the original participants of this thread are still with us?

There was quite a bit of misinformation in this thread with regards to E85. E85 is a cleaner burning fuel that allows the engine to make more horsepower. The GMT900s have different fuel maps for it.

The ultimate measure of a fuel's efficiency is how much does it cost to drive per mile. For example, using the highway mileage in post #6 above, it costs $.13 cents a mile to drive using 87 and it costs $.12 a mile for E85. Clearly, in this example, E85 is less expensive fuel to use.

The ability to use E85 exclusively on a cross country trip is highly suspect though. For one, the vehicle's range is less and the stations offering E85 can be quite sparse in many areas of our nation.

The fella who authored post #5 reveals what those who record their mileage have long known, that all fuels are not the same, either by octane or brand. I can always count on Shell's gasoline to lose 2 miles per gallon with their 93 octane offering compared with Sunoco's. We get 1-2 mpg better than Sunoco's on Mobil's 93 octane.

Been thinking of running a tank or two of e85 lately since I found a station by me with $1.96. What's your experience with one brand over another for the ethanol? This joint is a speedway and I never buy my gas there. Is there any "adjustment time" when switching back and forth? Is there a best practice like running it as empty as you can? Are there any detriments to switching, is there a too often?

 

[swathdiver]

Been thinking of running a tank or two of e85 lately since I found a station by me with $1.96. What's your experience with one brand over another for the ethanol? This joint is a speedway and I never buy my gas there. Is there any "adjustment time" when switching back and forth? Is there a best practice like running it as empty as you can? Are there any detriments to switching, is there a too often?

You don't have to run it down to empty but in doing so will maximize the ethanol alcohol content. One the one hand it will make more power and on the other it will get fewer mpg. It takes a tank or two to completely switch over usually and get your highest alcohol content. I have seen differences between stations before but not sure why. I reckon since none of them produce their own E85 (Shell, Racetrac and Sunoco) around here, they are all getting it from the same place. Just a guess. I never go to Racetrac either, save to buy icecream for the kids or E85, don't get my gas there. However, my daughter's little Kia Spectra got about 2 mpg more over Sunoco.

Each time you refuel, the computer detects a refueling event and begins recalculating the ethanol content of the fuel for optimum performance. It takes about seven miles so it is good to go for a little drive and let the computer do its thing. But that's for the GMT900s, not sure of the process for your L59.

Since I began making a written record of refuelings, Shell's E85 had a lower alcohol content than the others. Racetrac's started out the same and then went up into the 70s. My last tank of gasoline had an alcohol content of 12% and after pouring 27 gallons of Sunoco's E85 on top of it the alcohol content settled at 77%. My highest recorded number to date.

My truck got 18 mpg @ 40 mph, 17.3 mpg @ 60 mph, 16.2 mpg @ 65 mph, 15.2 mpg @ 70 mph and 12.9 mpg @ 75 mph yesterday. Cruise control, no stops or interruptions for at least 7 minutes and resetting the AVG economy each time and taking the reading from there after time. Roads were mostly flat and if going over bridge, held it a few minutes longer.

I was happy to pay $2.30 a gallon the other night for it, which equates to $.15 cents a mile when running at 70 mph on the highway. My best gasoline reading to date still cost $.19 cents a mile. Still a huge difference in savings over 300 miles. That's $12 saved.

Let me know how it turns out for you Nate.

 

[MCAT069]

I've never run E85 in the '12 Z71; however, I am intrigued by this conversation. So, after 2 tanks of E85, I should have the regular gas flushed out? I want to do one of these test analysis here in flat West Texas.

 

[kbuskill]

I've thought about doing this myself.... but E85 is not available anywhere close to me.

 

[swathdiver]

I've never run E85 in the '12 Z71; however, I am intrigued by this conversation. So, after 2 tanks of E85, I should have the regular gas flushed out? I want to do one of these test analysis here in flat West Texas.

More or less, yes. Another round of tests completed:

http://www.tahoeyukonforum.com/threads/useless-information.97483/page-29

We'll be taking on another tank today or tomorrow and will run the tests one more time. That'll be the third tank since switching off of gasoline.

 

[swathdiver]

I've thought about doing this myself.... but E85 is not available anywhere close to me.

What pat of Jax Ken? I see three Racetracs, a Wawa and a Circle K at first glance on the Gas Buddy app. Circle K's price though is crazy. The Racetrac at 103rd and Harlow has it for $2.36 a galleon.

 

[kbuskill]

What pat of Jax Ken? I see three Racetracs, a Wawa and a Circle K at first glance on the Gas Buddy app. Circle K's price though is crazy. The Racetrac at 103rd and Harlow has it for $2.36 a galleon.

I actually live in Middleburg which is SW of Jax. I downloaded the gas buddy app and set it to show E85 and there is nothing close.

Edit... looks like a gate station has it... 12 miles one way from my house... lol

 

[swathdiver]

Careful with that little station, they might be real proud $$$ of it! Better to wait until you have an excuse to drive into the city and get it from a station that moves it with regularity.

 

[kbuskill]

Careful with that little station, they might be real proud $$$ of it! Better to wait until you have an excuse to drive into the city and get it from a station that moves it with regularity.

Gas buddy says $2.29 for E85.