LML Fuel Economy

[cowboywildbill]

I have noticed big differences in mpg on my last 3 d/maxes when going from summer to winter blend fuel. The winter fuel seems to drop it a couple of mpg on average. But then maybe some of that is due to warming up and idleing in cold weather. And now with remote start that add's more idle time. Spoiled "haft" to go out to a warmed up truck now. LOL
How did we survive before all of that?

[SoTxPollock]

Changing fuel filters 3 times in 4 fillups. Why? You are probably loosing fuel each time you remove a full filter some probably runs out before you can get the new one on. Let it run a few thousand miles, oh and by the way , my fuel mileage continued to increase for about 60,000 miles incrementally just a little every few thousand miles, it took that long for the engine to feel like it was finally broken in. Once you've got the engine and drive train broken in where it runs more free, you should see your mileage increase. I've followed WildBills posts for years and you may just as well believe what he tells you because no one has a good enough memory to lie about something, they will always get caught. I've never heard him say anything that contridicted what he previously said in other posts. I have a good friend with a 2011 and he says he's only getting about 14 mpg. One day I looked at his new truck. It's got a giant steel flatbed with double heavy headache rack, there are two tool boxes loaded, an auxillary fuel tank that he had special made that holds 150 gallons of diesel, he's got chain saws, shovels, tools of all kinds strapped to it. The back seat is folded down and so help me there is not room to put a lunch pail in the back seat, it's stacked to the headliner with stuff he uses in his fence building business everyday, so he never unloads anything. He's usually towing a 16' lowboy trailer with a bobcat on it with fence posts pile up 4 feet deep and he wonders why he can only get 14 mpg. I asked him what his previous F**d truck got and he said you don't want to know and besides it cracked two sets of heads on that 6.0. I assured him the only reason he will have to get rid of the Chevy is because he wants a new truck. It's not gonna break and it's not gonna wear out, unfortunately he will never know what mileage it gets empty, because it never gonna be empty while he owns it.

[Mark Rinker]

I have been flogging the snot out of my 2009 since I bought it with 15K miles in August 2010. Fast forward to November 2011 and it has 83K and the towing mileage average is solidly superior to either LBZ I ran prior.

It pulls harder, rejects heat better, and on the rare occasion that I drive it empty it gets 21mpg.

Like a freekin' rock!

[toneash]

I have a 2012 2500K with a Duramax and Allison Transmission. I am getting 16 mpg empty driving partially highway and city. I was wondering what kind of mileage I can see during my trip to San Diego. Going there unloaded but pulling a uhaul trailer with a 2004 Pontiac Grand Prix back.

[chessy56]

From these posts, it sounds like a new LML's fuel mileage isn't too far off of what I was getting when my LB7 was "new"- about 15-17 combined C/H driving. After a good break-in period, my mileage began climbing. It's now got 270K on it and frankly, mileage has become a reflection of just how heavy my right foot is! The LML, as I see advertised, is supposed to get better fuel mileage than its predecessors, but my LB7 will get (empty) ~21 mpg (highway) at 65-70 mph. Back that speed down to ~57 mph and I get better than 25- no B.S.!!!

Once these new LMLs are "broken in", I wouldn't be surprised to learn of highway mileage in the 20s. The biggest challange for any driver is having the "patience" to drive at reduced speeds.....

[ChevysRus]

Just picked up my new truck, also my 3rd Duramax. Had a great '01, better '07 and hoping this one is a great '12. Had 9 miles on it when I picked it up, drove it about 50 miles around town and hooked up my 28' Haulmark (empty) and drove 850 miles from Seattle to San Francisco to break it in LOL. Averaged 13.2 MPG right out of the box.

Headed back in 2 weeks with the car trailer loaded with my '57 Chevy for GoodGuys Puyallup Car show. My '07 got 13-15 MPG towing loaded and 17-18MPG around town, no trailer. Expecting same or better from this new truck. I do like all the improvements with or without better mileage.

I sold the '01 at about 75K and traded in the '07 same at 76K. Great trucks, just higher value trading early every 5-6 years.

If you can afford one of these great trucks, don't worry about mileage, diesel today is a buck cheaper than it was 4 months ago. Enjoy it while it last LOL. These trucks get you where you are going faster, safer and with more comfort than we really need. The braking, tow/haul and the new exhaust braking all results in less white knuckle adventures as well.

With my favorite car in the box and my family and grandkids in the cab, I want a truck that is big time overkill for the job at hand. Duramax gives me that confidence. Many years ago I did same towing with a 1500 gasser. Talk about being on the edge of disaster all the time. Young and foolish back then.

Anyway, just enjoy the trucks and don't sweat the small stuff.

[ceide4489]

I have a 2013 2500HD and when I purchased it I manually checked cause the truck said I was getting 19.5 and I am getting this when done by hand. I have recently put a BDS lift in with 35" mud tires and am getting 18MPG

When towing my small holiday trailer under 5000 pounds I get 14-15MPG

These numbers are considerable better than the 2011 I had prior to this and not really sure why. I didnt think they changed anything

[kelloso]

I own a 2011 GMC 2500HD LML and I am getting 20-22 empty, 13 if its in REGEN. Towing my TT I am getting around 12-15 on flat ground running 60. Thinking about trying that Dura Mileage for the LML, claims 4-7 MPG empty running the 90HP tune. Any thoughts?

[GM Customer Service]

Y'all can check out http://www.fueleconomy.gov/ for some extra tips on how to save on fuel! Every little bit helps these days. Happy travels,

Kelly J.
GM Customer Care

[dougmac]

My 2013 LML: 20.5 on the highway, 15-17 around town, 11.5 towing my 5000 lbs travel trailer over in the mountains. (checking manually... the DIC is a little more optimistic than the actual mileage)