I've got a 2012 4x4 2500 6.0 with the 4.10.
I got 11.5 mpg driving around mixed roads on the 87 octane.
I'm getting 12.5 with 92.
Towing I saw 7.5 pulling an around 8500lb Rubicon 2100.
The manual says you don't need the haul mode unless your 75% of your towing capacity. I used it in the mountains/hills. Didn't experience any hunting when it was flatter.
270wsmhunter wrote: I have a 2011 Silverado 2500HD CCSB with the 6 liter, 3.73 rear end, Z85 pkg, and 18" wheels. I was getting 10-13 bumming around no trailer, 8-9 with our Jayco. Then I started putting in 91 octane with no ethanol and my mileage had increased significantly. I now get on average 15.5 to 17 MPG bumming around and can see 19 to 22 MPG if given a calm day or tailwind. Towing the Jayco I got 12-13 MPG. Truck currently has 11,700 miles on it and power seems to always be getting better. We are looking to upgrade to a 2013 Jayco Eagle 28.5 RLS 5th wheel so we'll see how it does then. Probably will wish we had the 4.10 rear end.
I WANT TO BELIEVE! I WANT TO!
I'm going to drain my tank, and find some ethanol free gas. If that works, I owe you a bottle of 12 year old scotch.
My best mileage has been on ethanol free gas. I dont need to buy the premium it's ethonal free across all grades. I have hit 16 mpg average (no tail wind assistance) over a 277 mile trip across Idaho. I doubt I will ever see 17 but my mileage has edged up since it was new. I fill using the nonethanol pump when at all possible.
2006 GMC 3500 CC 4X4 D/A
2013 Fuzion 342
2011 RZR Desert Tan
2012 Sea Doo GTX 155
2005 GMC 5500 CC 4X4 D/A
2012 Chevy 2500HD 4X4 6.0 3.73
I drive my truck daily 75% highway @ 65mph. I typically see 13.5mpg using 87 Octane, have not tried any of the higher octanes. I'm curious to see what I'll get in the summer here after they switch to a summer blend. If I do a straight highway / flat run I can do right around 15.5mpg, but my daily drive does consist of a lot of grade changes etc as I go through a mountain pass too and from work which is about 10-15ish miles of 2+% grade. 6th Gear, 1800ish RPM range, 3.73 rear end.
2008 Chevrolet Silverado 2500HD 6.0, 3.73, Firestone Air Bags, CCSB LTZ
Mitchellg: It might be hard to believe but it's true. I ran only a few tanks of ethanol blend (MN fuel) before switching over to running 91 octane non-ethanol. Really makes a difference. I'm not sure when I can get down to St. Louis but I suppose we can meet in between sometime at a campground and I'd even share that bottle with any and all who would like to partake.
APT: I put in the 87 non-ethanol when we go up to Fargo to visit my brother in law, no significant changes except on the pocket book. I wish MN would be more like ND in allowing the 87 non-ethanol but only non-ethanol option is 91 at 40-50 cents higher than 87 ethanol blend.
For the naysayers, when we went down towards Iowa last month we had a slight tailwind heading down and slight headwind coming back. We averaged 19.3 roundtrip for approx. 330 miles.
My only dilemma is when it's time to upgrade do I stay with the gas and continue to pay for premium or switch to diesel for similar fuel price, just that big bump for the upgrade.
2011 Chevrolet Silverado 2500HD Crew Cab 4x4
2011 Jayco 26BH
When I was pondering the truck purchase I figured it would take close to 7 years to 'save' enough money in fuel costs to pay for the extra cost of purchasing the truck with a diesel engine.
By my figuring switching to premium saves me about 4 dollars a tankful with the increase mpg.
270wsmhunter wrote: I have a 2011 Silverado 2500HD CCSB with the 6 liter, 3.73 rear end, Z85 pkg, and 18" wheels. I was getting 10-13 bumming around no trailer, 8-9 with our Jayco. Then I started putting in 91 octane with no ethanol and my mileage had increased significantly. I now get on average 15.5 to 17 MPG bumming around and can see 19 to 22 MPG if given a calm day or tailwind. Towing the Jayco I got 12-13 MPG. Truck currently has 11,700 miles on it and power seems to always be getting better. We are looking to upgrade to a 2013 Jayco Eagle 28.5 RLS 5th wheel so we'll see how it does then. Probably will wish we had the 4.10 rear end.
Did the sudden increase in MPG also coincide with you putting around 10,000 miles on the truck?
Somewhere between 10,000 and 15,000 miles, the engine finally breaks in and your power and fuel economy suddenly jump way up. On mine, the MPG went up 33% at around 15,000 miles.
Getting rid of the ethanol had some effect, but it's not responsible for the entire improvement...
2002 Chevy 3500 DRW 8.1L/Allison
2000 Palomino B1500
...and the reason why I need a DRW to haul a Palomino:
2004 United 7x14 tandem axle enclosed toy trailer
2011 PJ 8x20 7-ton deckover equipment trailer
Lantley wrote: 2008 Duramax to 2011 6.0 tough decision. I know the 2011 has the beefed up frame but giving up a Duramax would be hard to do. Was 2008 during the period when diesel MPG really suffered?
I think I'd want the Duramax if pulling 11.8K.
Had a 2006 D/A E/C. Went with the 2008 CC for the extra space behind the driver's seat. CC folds back, EC folds frontward and I could push my seat back all the way. The 2008 had that stupid "after burner" on it (never would have traded if I'd known that) and yes, the mileage suffered. In Ohio, diesel runs between .50 and .80 per gallon MORE than gas. And when D/W drives when towing, pulling into refuel you have to look for the diesel pump vs the gas pumps...some stations only have two diesel pumps. Just more convinent I guess. D/A pulled the TT without a hiccup. I'm sure the RPMs will be higher with the 6.0 on a hill but I'm a very patient driver and don't spend much time in the mountains. The D/A provides you with unlimited towing capacity but they are quite more expensive. I think the truck body and electrical stuff will fail before the engine gives out.
Vanda and Dave Ludwig (Vandave) Spoiled King Charles Spaniel, Ultra spoiled Cock-a-phoo, '12 2500HD, 4WD, CC, SB, 6.0, 4.10, 30U Arctic Fox, Equalizer.
270wsmhunter wrote: Mitchellg: It might be hard to believe but it's true. I ran only a few tanks of ethanol blend (MN fuel) before switching over to running 91 octane non-ethanol. Really makes a difference. I'm not sure when I can get down to St. Louis but I suppose we can meet in between sometime at a campground and I'd even share that bottle with any and all who would like to partake.
Can't buy any ethanol free gas in St.Louis. It's actually illegal in St.Louis county.
Tried running 93 octane. Over the last tank of gas I averaged 14.46mpg. That's odo mileage divided by gallons to fill up. That's almost a 2gallon MPG bump for right at 20 cents a gallon. I was getting 12-13mpg.
Doesn't make it worth it. Going to try out the 93oct while towing and see how it does.
270wsmhunter wrote: I have a 2011 Silverado 2500HD CCSB with the 6 liter, 3.73 rear end, Z85 pkg, and 18" wheels. I was getting 10-13 bumming around no trailer, 8-9 with our Jayco. Then I started putting in 91 octane with no ethanol and my mileage had increased significantly. I now get on average 15.5 to 17 MPG bumming around and can see 19 to 22 MPG if given a calm day or tailwind. Towing the Jayco I got 12-13 MPG. Truck currently has 11,700 miles on it and power seems to always be getting better. We are looking to upgrade to a 2013 Jayco Eagle 28.5 RLS 5th wheel so we'll see how it does then. Probably will wish we had the 4.10 rear end.
I WANT TO BELIEVE! I WANT TO!
I'm going to drain my tank, and find some ethanol free gas. If that works, I owe you a bottle of 12 year old scotch.
My best mileage has been on ethanol free gas. I dont need to buy the premium it's ethonal free across all grades. I have hit 16 mpg average (no tail wind assistance) over a 277 mile trip across Idaho. I doubt I will ever see 17 but my mileage has edged up since it was new. I fill using the nonethanol pump when at all possible.
I ran our truck down to the low fuel warning (perhaps 4-5 gallons left) and then filled with non ethanol 87 last night. We got on the freeway and watched the mileage climb on the display. 17.3 mpg after ~10 miles on freeway at 60mph. It dropped to 16.2 mpg running at 70mph (actually worse than that since I did not reset, it was average of 60mph and 70 mph sections). Ran a few errands, mileage climbed back some on the way home.. I would guess about 1-2mpg increase using non ethanol gas. It was $.40 higher for the non ethanol. Next tank will be 91 octane to see how that does. I don't put alot of miles on so we'll see how the whole tank does.
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