2011 Duramax DEF mileage

mikeandconnie

Well-known member
Hello

I'm taking my 2011 Duramax in for the first service tomorrow and having them check the DEF system at the same time. It's seams to be using too much. May I ask how many miles others are getting per tank 5 gals?

Thanks,

Mike
 

Hastey

Oklahoma Chapter Leaders
My 2005 is getting 10 mpg on the flatland, less in the big hills. Thats towing a 34 ft Sundance.
 

mikeandconnie

Well-known member
LOL . I'm happy with the fuel mileage 17 mpg flate land 14 in the hills towing 16000, but it seams I'm only getting 1500 miles then I have to stop for DEF,
My 2005 is getting 10 mpg on the flatland, less in the big hills. Thats towing a 34 ft Sundance.
 

danemayer

Well-known member
I got around 4500 on the first 5 gallons. The next 5 went a lot longer because the system seemed to get screwed up in Colorado in January and had an error msg that wouldn't go away, though the tank had 4 gallons and I added one. Between mid-Feb reset of the DEF system and early June, at the next oil change, it seemed to use zero DEF over several thousand miles. The dealer found no errors and it now seems to be working normally. I got a low DEF msg at about 4500 or so since the oil change/DEF fill.
 

jddugan

Member
Most people I've talked with use about 1 gallon per 1,000 miles. That's also what mine has been averaging.
 

Rickhansen

Well-known member
They say it differs greatly based on load, I topped off my DEF yesterday, in fact - 2.5 gallons in about 5100 miles. All of that was running empty, not towing. Also happy to say I'm getting 19.1 mpg combined driving. The best fuel mileage I've gotten is 21.9 mpg on a recent trip ~ 600 miles running about 63 miles per hour.
 

Chainsaw

Saskatchewan Chapter Leader
Rick is that loaded miles? I have just ordered a 2011 duramax dually, will pick it up when we return from Oregon
 

kakampers

Past Heartland Ambassador
We got our first DEF warning at just over 5,300 miles...we're now over 11,000 miles and still waiting for the second warning...should be soon I suspect. As for mileage we're averaging about 12 mpg towing, and our rig weighs in at just over 26,000 lbs. Running around town we're averaging just about 15 mpg and straight highway without towing we're getting just over 17 mpg....so far VERY happy with this truck!

Hard to believe it out does EVERYTHING that the 2005 Kodiak could do, and I mean everything, including handling our load and especially stopping our rig and slowing it down on steep grades...and the comfort level over the Kodiak isn't even comparable...glad we made the switch.
 

Chainsaw

Saskatchewan Chapter Leader
Thanks, ours weighs in at 26100, I presume the 3500 will bring that weight up a little.
 

JohnDar

Prolifically Gabby Member
Thanks, ours weighs in at 26100, I presume the 3500 will bring that weight up a little.

You can figure a GMC 3500HD D/A Dually Ext. Cab weighs in at 8040 lbs. That was CAT scale weight with just me (165 lbs.) a full 34 gallon (OEM) tank, a few tools, the hitch, and no trailer.
 

kakampers

Past Heartland Ambassador
Chainsaw...Our 3500 DRW weighed in wet at 8,750 lbs...that was two people, two dogs, full fuel tank and everything else we carry in the truck, which isn't much...our actual total wet rig weight was 26,350. Your Landmark must be extra heavy, like our Bighorn is to weigh that much BEFORE the dually!!
 

mikeandconnie

Well-known member
Hi again, I call several GM dealers today about my DEF problem, they all told me the same thing, it's the way I drive it. Which I have only 6000 highway miles 2200 towing at 65 mph. So I call GMC and they looked up my VIN and there's a recall on my truck as of July 17, for this problem.. It was fun calling the dealerships service managers telling them they need to do there homework and read this Recall.... They are reseaching now and going get back to me to explain what's involved to do the repair. I think a program, but not sure.
 

Vtxkid

Well-known member
With only 1,350 miles on my 3500, I haven't had to deal with the DEF fluid refill yet... but, I have 2.5 gallons ready for when that time comes.
 

Rickhansen

Well-known member
Rick, is your GMC a dually. Mike

No Mike, It's a 2500 crew cab, 4x4, SRW. I didn't consider a dually as 98% of my use is a daily driver. I'm sure the dual wheels help the stability some, but the 2500 / SRW offer acceptable load ratings, make a better everyday vehicle for me, and I've had no issues or complaints towing with it so far.

For the past week, it has developed a very hard to start condition intermittently that's worrying me. I suspect either a weak fuel pick-up pump in the fuel tank. Onstar remote diagnostics reports no error codes, but I have yet to get it in to the dealer. It runs fine once it starts, but you shouldn't have to wonder with a new vehicle. Beside that I've been driving about 220 miles a day for work. I figure if it gets better or worse before I get it in, it will make troubleshooting easier.
 

Hastey

Oklahoma Chapter Leaders
Hi again, I call several GM dealers today about my DEF problem, they all told me the same thing, it's the way I drive it. Which I have only 6000 highway miles 2200 towing at 65 mph. So I call GMC and they looked up my VIN and there's a recall on my truck as of July 17, for this problem.. It was fun calling the dealerships service managers telling them they need to do there homework and read this Recall.... They are reseaching now and going get back to me to explain what's involved to do the repair. I think a program, but not sure.

LOL! I was reading this and had to call a guy I know who happens to be the DURAMAX Mech at a dealership. He said that he didn't know S - H duble hockey sticks about it but would be looking into it tomorrow.
 

JohnDar

Prolifically Gabby Member
Is it a Service Bulletin or an actual recall? Many times, service bulletins get addressed if a customer brings their vehicle in for service, even if it's unrelated to the problem. A recall gets you a letter in the mail to bring it in.
 

mikeandconnie

Well-known member
It's a Recall for calibration of the DEF per my VIN. Date July 18, 2011. it may not effect all 2011.. I'm sure my need somthing. My tail pipe is white and I'm only getting 1500 miles per 5 gal... I was able to fill up at the Pilot Bulk DEF pump at 2.50 Gal, so every thing is cool.. GM today quoted me 25 buck for 2.5 gal... I said no thanks. I kinda use of filling it myself. Thank everyone for the info..
 
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