D-max mileage??

[OL Creeker]

My '13 Duramax/Allison gets 16mpg, not towing. I thought it would be higher.

[Shaun_McD]

Brand new trucks will do better after they break in. Your MPG average should increase over the next couple years.

[force]

Originally Posted by joenic53

I don't mean to hijack this thread but if someone could explain why the main choice of diesel is 4 x 4 and not 2wd, unless you do a lot of off-road driving. The 4x4 seems to have more resistance and maintenance issues compared to 2wd. Just looking for some info

I live in New England, and snowmobile in the winter, so 4x4 is a must for me.

[EXGMTech]

Originally Posted by joenic53

I don't mean to hijack this thread but if someone could explain why the main choice of diesel is 4 x 4 and not 2wd, unless you do a lot of off-road driving. The 4x4 seems to have more resistance and maintenance issues compared to 2wd. Just looking for some info

all you need is some wet grass, slight incline, and you will play sit-n-spin trying to tow your rig

[BarryD0706]

I have 2wd and have had no problem so far. The parks I go to all have paved roads.

[MillerTime]

To OP
- on the '06 dmax there is an option for egr clean/scrub function that is available with a scanner that will control functions. It wouldn't hurt to try- but will blow a little smoke as it is blowing the gunk out afterwards. Of course we ( techs) would always recomend keeping everything stock on powertrain, even down to oe filters, fuel, air etc.- ( k&n are not good air filters at all imho, too restrictive or not enough depending on conditions, amount of oil used and humidity)

- on '07 on up dmaxes watch your idles, short trips etc. The less regens you have the better ( they tipicaly use about 3 gal of fuel during regen) but if you do have a dirty particulate filter it will bring mileage down too.

- if you have a newer diesel - make nice with a tech that has a computer that can communicate with the trucks computer- there are a lot of specific functions available to them that will benifit you and save some $ at a dealer- just ask a tech at your dealer, someone will tell you of a guy who does stuff on the side.

[FR28footer]

Originally Posted by Twisty

"the older dmax gets better mileage"

"22 highway" from a "2012 Silverado 3500HD"

How far do we need to take this?

Why would I lie? I get that mpg unloaded and on the highway.

What are you implying?

I have no aftermarket anything other than a 5er hitch, tonneau cover and mudflaps.

Lighten up. At 60mph i am at 1400 rpm. Relax. Get a Chevy.

[jasonamar]

I have a bone stock 2011 2500hd 4x4 crew shortbed with 49000 miles LML Duramax which is the newest Duramax with the DeF system on it and on the highway at 70-78 mph I can see 20-23 mpg. With my old 26ft Jayco steel TT I was seeing 12-14. With my new 355qbq this is the first trip averaging 70 mph we saw 9.5-9.75 mpg so far with the new one

[win]

I have a 2012 2500 HD LML D MAX and I get 16.5 mpg in the city and 19.5 highway keeping it at 60mph @ 1400 RPM, 4000 miles on the truck should get better as it gets more miles
Haven't had a chance to tow yet but will in the next few weeks
But over all im impressed, my 2007 5.9 Cummins was about the same, less h/p less torque

[jevanb]

Originally Posted by FR28footer

I get that mpg unloaded and on the highway.



At 60mph i am at 1400 rpm. Relax. Get a Chevy.

you are prob looking at the DIC which is always wrong, everyone I know gets worse milage, I also have a 6 speed and I see 1600RPM at that speed and we also have the same final gear set, but at that speed I am at 5th not 6th, the only diff is your tires size

[jasonamar]

Mileage divided by gallons I know the DIC isn't right never has been

[jasonamar]

My DIC says 13.6 mpg since new I've never reset it also my OnStar app says the same thing but that's loaded and unloaded combined since new about 60% of my mileage is pulling a trailer or load

[FR28footer]

Originally Posted by jevanb

you are prob looking at the DIC which is always wrong, everyone I know gets worse milage, I also have a 6 speed and I see 1600RPM at that speed and we also have the same final gear set, but at that speed I am at 5th not 6th, the only diff is your tires size

Wrong. In 6th. 18" wheels. Not looking at the dic. Why the arguments? Oh well.

[win]

Originally Posted by FR28footer

Wrong. In 6th. 18" wheels. Not looking at the dic. Why the arguments? Oj well.

X2

[Shaun_McD]

Fuel mileage discussions always end the same. Vast varying reports some un-explainable low MPG numbers and some that are so high you question the accuracy or truthfulness. Typical is probably somewhere in between. Also keep in mind driving habits, average speed ect. Lots of things are going to make these MPG reports vary a lot.

[camper1999]

On my 2011 GMC I get 11-12 towing a 12,000 pound trailer and 20-22 on the highway not towing. I manually calculated it and viewed the DIC, pretty much the same. Towing with my previous gasser got 8-9 towing a 8,000 pound trailer 50% improvement in mpg with the diesel towing 4,000 pounds more!

[TURBS]

Originally Posted by camper1999

On my 2011 GMC I get 11-12 towing a 12,000 pound trailer and 20-22 on the highway not towing. I manually calculated it and viewed the DIC, pretty much the same. Towing with my previous gasser got 8-9 towing a 8,000 pound trailer 50% improvement in mpg with the diesel towing 4,000 pounds more!

X2 manually checked against dic and found mine to be very close .

[MillerTime]

Mine is usually with in 0.1 or 0.3 from dic to manual calculation.

*This is why peoples # don't always match-

You would be surprised to know how many vehicles have the wrong tire size calibration downloaded. And sometimes the door sticker size doesn't match the calibration. This is easily adjusted at a dealer or at a shop that has a scanner that will do it.
Ps. I change tire sizes frequently so I calculate my % diferences in tire sizes when running my larger tires