E85 Flex Fuel Do you run it yes or no

[08_Lanche]

I personally do not run flex fuel in my 08

 

[BucksOSU]

I have been doing E85 calculations since I purchased my 08. (I now have a '13) You MUST pay at least 20% less at the pump for E85 to even consider it feasible from a dollars and cents standpoint. I have no idea about the performance differences because every time I have used it, I couldn't wait to burn it off and buy real gas again. If I averaged 18-20 MPG on the highway with standard 87 octane, I would get more like 15-16 MPG with this stuff. However, with that said, you should all try E88 gas if you can find it near you. I buy it at Sheetz here in Northeast Ohio. It is always cheaper than gas and I see absolutely no difference in mileage. Supposedly it is 15% Ethanol compared to the standard gas being 10%.

 

[Wpolonavyguy]

I'm considering giving e85 another shot as here almost 7$ a gallon regular gas. E85 still about 3.99 a gallon might have gone up 4.99 since I last purchased.
I may try E85 tank then regular/ back & forth with cat cleaner every so often?

When I ran 3to 4 tanks e85 only cat performance code tripped, cleaner & reg gas went back to normal.
Price climbing high again might give e85 another chance see how it goes try saving some $$$

 

[rocknss]

My 07 runs E-85 with no problems, I have only bought E-85 from a Shell station so maybe it could be where people are getting the E-85 that are having issues with it.
I also added a flex fuel sensor and tuned my 17 Camaro 2SS and have had no issues running E-85.

 

[Rbattaglia1]

I ran my 2006 over 100,000 miles on it with no issues and my current 2013 has over 120,000 and running with no issues. That being said because of the mpg there must be at least a 60 cent delta for the price to be worth it. Also i heard its not good to use e85 in very cold temps so here in Chicago i use regular gas when the temp is below 35 degrees.

 

[redheadedrod]

E85 has less power for gallon so it does require more volume to get the same power. However it also cools your intake down allowing more air into your intake. So it does actually give you a little bit more power. In my CTS with a Direct Inject setup it is a significant boost. The more compression you have, the more power you gain from E85. Have an Exgf that had a 2013 truck. She dropped from like 22mpg to 18mpg. And her 4 cylinder mode wanted to kick in more often when on the highway. It definetly added more power to her truck but not the 40-50+ hp it adds to my CTS. Right now with the temps in the 30's I am getting a significant boost in power from E85. The little 3.6 in my CTS almost feels like I have a 100hp NOS kit in it with E85 over regular gas. Never heard of an issue with Cats or O2 sensors. But you also can not swap back and forth between E85 and normal gas. The Flex Fuel manual tells you that it requires 2 tanks of gas for the engine to adjust properly to having it or not having it. Your fuel mileage will dramatically drop during this "learning" period and you may find some weird runability issues. Love running E85 in my CTS in the summer. Its like a totally different car on it. My truck is not flex fuel (yet) so nothing to say about that for it. With the new system it will be sized and made compatible with E85, but been told with the pre-2006 trucks PCM, they don't handle E85 very well.

 

[Jeff 222]

I just want to see how many of us 2007 newer 5.3L Flex owners Still run the E85 Flex fuel or not, and hears why.

Last year when I had my 07 at the Dealer for repairs, they told me not to run Flex fuel because it was bad for the engine even though the engine was designed and built to run E85 flex it was bad for it.

But now that in my area regular gas is up pass $6.00 a gallon and E85 is almost $2.00 cheaper I was thanking about when I'm near the only station in my area that has it to fill up with it.

I was reading on the station's web site that the average octane for E85 is 100 to 105.

I would love to try the 85,,I was told that it burns hotter,, then out should clean the injectors, right,, Jeff

 

[Loowwride]

I would love to try the 85,,I was told that it burns hotter,, then out should clean the injectors, right,, Jeff

I still run E85 in my 07 my Avalanche runs great I can feel a little more power when I do but it does burn faster I lose about 4 miles per gallon

 

[batmanntexas]

I've been running E85 in my Avalanche for at least the last 3 years, almost exclusively. Granted, I have a fully built motor, supercharger, custom fuel system, etc., but it's still a GM LS engine and computer at work.
I think all of the cases of performance issues while on E85 are due to the way GM implemented their Flex Fuel strategy. Meaning, they chose to utilize a 'virtual' sensor (at least on mine anyways) instead of an actual fuel content sensor. The difference is dramatic. The virtual sensor only measures ethanol percentage when the ECM detects a fuel fill up, and then uses the O2 sensors to determine the ethanol percentage. Only then will it apply the appropriate 'tune' adjustments to optimize the engine calibration for the increased ethanol percentage. An actual fuel content sensor is continually reading ethanol percentage and supplying this information to the ECM, which adjusts the tune in real time.

Power and drivability should be the same, if not better, on E85. The only thing that should suffer is fuel mileage....to the tune of about a 30% decrease in economy.

 

[Capt.Crunch]

I go to a local station called Casey's, they have E-15 gas an alcohol blend, it's 88 minimum octane and it's about 25 to 35 cents cheaper than the regular 87 octane gas, my Avy runs better and has a whole lot more power than using regular unleaded or even the higher octane unleaded fuels, my fuel mileage is a lot better, about 3 to 4 more miles per gallon, depending on how I drive it,lol, but I have a Diablo Predator 2 tuner that I recently used the 91 octane program on the computer and I'm very very satisfied with it, I can actually light up 35" tires on dry ground and I couldn't do that in the past. The only thing I don't like about the Predator is it changes my transmission settings by itself and I don't know what kind of pressures my trans pump is putting out, I'm terrified of ruining my transmission again, it's still under warranty for another year, but if they were to find out I changed the settings it would probably void my warranty.

 

[Allniter 007]

Yes I run E-85 80% of the time station on the corner has it.

 

[Capt.Crunch]

I have a 2010 LTZ and I run the alcohol blend 88 from Casey's, my truck runs sooo much better and I get better fuel mileage. It's only about 20 cents cheaper than regular gas but it saves me a little bit of money and my Avy really likes it.

 

[Lewynn]

I used to run non ethanol in my 03 with full synthetic..never had issues, but I did accidentally put E85 in it (about 10 gals) and I freaked out about it, lol.. I called my son right away and he told me to go get some sea foam and put in it.. I haven't seen anything yet about if it's a good idea to use non ethanol in the 2013's. I filled it with 93 just after my son finished the tune up and put some engine cleaner through it.