Mileage on Duramax

[TSchleff]

Five years ago I purchased a 2009 2500 Duramax and loved the truck. Didn't have any issues and when towing the trailer, normally got around 13.5 miles per gallon. I usually drove at 65 to 67 mph when towing.

Just recently I traded in the 2009 for a 2014. Couldn't believe the incentives and for how little this cost me. I know the 2015 2500s and 3500s are now showing up in the showrooms with the new redesign and that is why they were wanting to push out the old body styles, but there is a lot of difference between the 2009 and 2014, so it was a big difference for me. I also went from a LT to the LTZ package.

My question for all of you 2011 to 2014 Duramax drivers is what kind of mileage have you been getting when both towing and driving around? Will I get about the same as the 2009? Or better? Or worse?

Please comment on the engine brake and how that has worked for you. I learned quickly with old truck, going up hill was no issue, but going down hill is much more important.

[dznf0g]

In my demos, and my 30' classic I get 11.5 - 12.5 on highway....but I never get a chance to drive them past 7000 - 14,000 miles. They're still pretty tight at that low mileage.
Engine brake is AWESOME. I pulled through the rockies from AZ to CO, taking all the scenic routes I could. All I can say is the engine braking is MORE impressive than the oodles of diesel power.

[moosetags]

We have a 2011 Chevrolet 3500 4WD Duramax, crew cab, long bed, single rear wheel. LT. His name is Fred. We custom ordered Fred to get exactly what we wanted, and took delivery in August, 2011. Fred is the first year of the LML Duramax, and uses diesel exhaust fluid (DEF).

We have now had Fred for 2 1/2 years, and he has almost 70,000 miles on him. Fred carries an Outfitter pop-up truck camper just about all the time. The camper weighs 3,300#. We also towed the 25FB Airstream about half the time.

Fred's fuel mileage has remained pretty consistent. He routinely get 11.5 mpg while towing the Airstream, and he gets 12 mpg with just the truck camper on board. I have found that there is not a lot of difference in mpg between towing and solo. Fred and the truck camper together weigh-in at 11,600#.

We have recently replaced our 2005 25FB with a 2012 23FB. I figure that this will shave at least 1,000# from our total rolling weight. I doubt that this will have any significant impact on Fred fuel mileage, but we don't yet have enough experience with the new Airstream to tell.

All this being said about Fred's fuel mileage, I would also like to comment on Fred's overall performance.

The DEF thing is kind of a pain, but I usually buy it at Wal-Mart on the run and add it to Fred in their parking lot. Fred has been getting about 1,000 miles per gallon of DEF. The 2011 Silverado doesn't have any DEF gauge, only a low DEF warning in the Driver Information Center.

Fred's overall performance has been excellent. He has carried his 19,000# total load without complaint. I am able to use his cruise control without the excessive downshifting that I used to experience with the 3/4 ton Suburbans. Even on fairly significant up-grades, Fred just reaches down into his giant bag of torque and motors up the hill without complaint or downshift.

Fred's exhaust brake function is most excellent. On significant downgrades he maintains speed without turning into that "runaway train" feeling that we used to sometimes experience with the Suburbans. This feature alone makes the diesel thing worth the extra expense.

Fred's integrated trailer brake controller also performs flawlessly. We have extensive towing experience with two 2500 Suburbans using both the Tekonsha Prodigy and P3 trailer brake controllers. These work well, but not as well as Fred's unit.

Other than routine maintenance and a set of Tires, Fred has had no repairs. We are quite pleased with Fed's performance. We went with diesel because when we introduced the truck camper into the mix, we were well beyond a gasoline truck's capabilities.

We made the switch to diesel reluctantly, but out of necessity. Now that we have some extensive diesel towing experience, I don't think that we will ever have another gasoline-powered tow vehicle.

Brian

[moosetags]

I understand that the newer LML engine Duramaxes now have a DEF gauge.

Does anyone know if the 2015 Duramax engine will still be an LML?

Brian

[SafariSS]

I do not have a duramax however i just sold my 2003 Suburban K2500 with 8.1 and the trucking company that came and got it had a duramax dually pulling a three car hauler trailer. I inquired with the driver how his truck was and how many miles he had on it.....810k!!! Only major item replaced was the turbo.

Said the transmission was original as well, just maintenance.

[av8or]

Naming a truck? You gotta be kidding.

[Rocinante]

Be nice, eh?

[AL’ UM- MONEY]

I have a 2011 dura max 2500 with 16,000 miles.i have pulled a 31 foot some with it but not a lot. I really don't know how to trust the on board computer as I have never measured gallons times miles. I almost always show 15.0 mpg. Because I don't tow that much the amount of DEF has not been a factor to me.

[SteveSueMac]

2013 Z71 extended cab short bed. The computer says 15.1 over 18000 miles (that's all inclusive of regular and towing). I haven't recorded this but I think I've done about 15-20 gallons of DEF so far. On my next trip with the trailer, I'm going to manually calculate mpg and compare with my computer.

[moosetags]

Originally Posted by av8or

Naming a truck? You gotta be kidding.

This is a really significant contribution to the issue being discussed.

Brian

[SteveSueMac]

Originally Posted by SteveSueMac

2013 Z71 extended cab short bed. The computer says 15.1 over 18000 miles (that's all inclusive of regular and towing). I haven't recorded this but I think I've done about 15-20 gallons of DEF so far. On my next trip with the trailer, I'm going to manually calculate mpg and compare with my computer.

Forgot to add. A lot of my driving is short distance commuting to work, medium commutes between CT and MA and then the towing. Usually drive 65ish on the highway, sometimes less when towing.

Also, my truck is named the Freedom Machine :-)
I got no problem with that!

[Tater]

Originally Posted by moosetags

I understand that the newer LML engine Duramaxes now have a DEF gauge.

Does anyone know if the 2015 Duramax engine will still be an LML?

Brian

Yes, the 2015 will be an LML. I have one on order and awaiting delivery. No change I don't believe until 2017 model year. New emission requirements about that time as well.

[moosetags]

Thanks for that info. If the LML runs through 2016, that will make it the longest running Duramax version by a couple of years. The LMM only had a three year run.

I would like to hear about the 2015 that you have on order.

Brian

[Tater]

2500 LTZ, 2wd, every option except power rear window and sunroof. Our first diesel in 30 years. All others were gas. It had been sitting in ft Wayne since Feb 3 awaiting shipping. Dealer invoice plus tax tag and title. It's a double cab (extended cab). Club cabs are coming from flint and shipping much faster.

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