Big_BlueFX4

My truck is still pretty new with less than 1,000 miles ad only put the second load of gas in this morning.

The first refill of gas I used 85 because everything says high altitude octane ratings are different and 85 is equivalent to 87. What I did notice with that tank is the dash fuel economy dropped by 3.5 MPG over the dealer's full tank they so graciously gave me.

On the second tank refill I went to 87 octane. So far after about 75 miles, there is a 3.5 MPG increase over the 85.

I have no idea i this is normal but it's obviously no coincidence. I'll stick with the 87 and see if the increased fuel economy holds up.

mrpositraction

LOL, I switched from 87 to 93 and back to 87. I liked how it ran on 87, but it was different gas, different station.

When lugging the trucking I can feel a very very light vibration/shudder. I think it is the the 6 cylinders versus 8 cylinders smoothness I have mentioned before.

energie

I had that problem you were talking about where the light came on, shuttered and then i pulled over, shut it off, turned it on and it was fine. took it in, dealer said it was a misfire. Said if it happens again to let them know, hasn't happened since.

Den17296

I use 85 here in Parker, Colorado and I'm averaging about 19+ mpg's with no issues at all

Joewee3.5

I've only had one tank of 87 octane in my truck in 8000 miles. It's been 93 octane from shell or chevron. My mileage is all over the place depending on wind direction or hills more so than anything. I also drove out off my way for several tanks of ethanol-free fuel. One thing is certain, ethanol-free gas gets better mileage every time.

superccs

I wish those horrid schmucks that thought up melting corn into gasoline would be buried in fireants. That crap destroys mileage like children evaporate patience.

tarheel - 2

I am running 87 in my screw. Have abt 5000 miles on the truck now, 4000 towing a 6000 lb trailer. Have some serious grades here in Western North Carolina ( 9% ) and have also operated in the nearly 5000 ft elevations of Western Nebraska. The truck seems to perform well on 87 octane - so well that I have not been tempted to try premium or midgrade fuel. I get between 8 - 11 mpg towing at 65 mph, and 17 - 18 without the trailer

sbronemann

Are you talking E85 or 85 regular gas?

bubbabud

My eco runs great on 87 but keep your eyes open when you travel especialy at higher elevations where 85 octaine is the norm. this is ok in a naturaly aspirated engine because they get less air thus less compresion ergo less tendancy to knock but your ecos turbos compensate for elevation and 85 octaine will run like crap. In these geographic areas premium is usualy only 89 octaine. bottem line if you need every ounce of power you can get run 89 or 91 fuel for most driving situations stick with 87 you will never make up the cost difference in MPG. and 87 will not hurt your engine in any way. BUBBABUD 2011 XLT SC EEEKoboost

bubbabud

E85 is an absolute NO NO he is talking 85 octaine reg unleaded gas.Bubbabud