[AKDoug]

I finally picked up my truck Friday night. I drove 303 miles between then and last night mostly highway speeds ranging from 60 to 75 mph. My first fillup was topped to the very top and took 17.7 gallons for 17.12 mpg. I'm extremely pleased for a couple reasons. First is that many were claiming much lower mileage on their trucks, and second I know that the dealership probably stopped filling the truck after the pump clicked off the first time. I managed to get 1.8 gallons in the truck after the pump clicked off the first time, so I could theoretically have gotten as good as 19.05 mpg.

I will be updating this thread since this is the first leg of a 6000 mile vacation for my family and I. I am going to keep a log of miles, fuel AND hours on the truck so I can calculate average speed per leg. As well as weather conditions.

BTW.. this truck will be stone stock with the 245 tires until I get home.

 

[AKDoug]

Pic of my new truck..

 

[Jasondt2001]

Man that's incredible, congratulations! I dont have that mileage yet - LOL
Drive safe; and enjoy your vacation!

 

[AKDoug]

2nd trip. Dunn, NC to Jamestown, VA.. 419.2 miles mostly freeway with a little around town stuff. 8.1 hrs of engine time for an average of 51.75 mph. Top speed on the trip was 76 mph for about 4 hours of the trip. Temps in the mid 30's the entire time. 24.65 gallons on the fillup for 17.0 MPG. Very happy still. 1152 miles on the truck at the fillup.

 

[Bill Martin]

My 06 LBZ now has 3300 miles; it's averaging about 14.5 overall. Bill Martin

 

[Chael]

I'm at 1100 miles and have averaged just under 15 mpg overall - best being 16.5, worst being 12.8, and lots of 14-15 in between. All ULSD.

One thing I have noticed is my DIC is all over the place. It has yet to show anything over 14.8 mpg, even though hand calculating regularly shows it higher.

Just added the 285's so I either need to recalibrate or figure out the difference in the calculation, which is about 64 miles for ever 60 according to a few online calculators.

Congrats on the mileage!

 

[projected]

Mine has just under 1700 miles on it. With mixed (stop/go & hwy) driving I've been just over 16 mpg since the 2nd tank (dealer filled me up at first 220 miles and I couldn't get the gallons) My worst has been 15.49 with almost all 4wd for 225 miles.

Yesterday I did a 150 mile round trip hwy drive (65-85mph) and had 50 miles mixed driving already on the tank when we left. Filled up at 213 miles and avg'd 18.2 mpg :ro) I'm extremely happy with that since 1/4 of the distance was mixed driving. I think 19mpg is doable with pure hwy driving. I can't wait to tow and break my LBZ in some.

Oh and I AM calculating for my 265's too.

 

[BIGR]

Reminds me of the first day I got my truck. I topped off the fuel, up the road from the dealer and took it on a short trip across the state line. Some reason I think after I get a new truck I have to drive it across the mountain to try it out. I got into the next state and topped off the tank since it was cheaper. I had averaged a little over 18 MPG. traveling at speedsfrom 55MPH to 60MPH. I was happy with that info.

 

[AK Edition DMAX]

Fairbanks to Anchorage

Right now in Fairbanks we are running stright D1 diesel because of the low temps...3 weeks ago we were -40...but thanks to global warming we are now moving above zero during the days. SEE there is a upside to global warming...we may soon be able to play golf in February...sorry that you near the coast maybe swimming.
Regardless...AKDoug...recently got 18mpg going from Fairbanks to Anchorage on D1...Anchorage is using a more D2 mix then us up north as the temps are higher there so on the way back up north I was getting 19mpg coming back up the Parks to Fairbanks...and that was fighting a headwind as anyone in Alaska would know is common.

 

[tuney443]

''One thing I have noticed is my DIC is all over the place.''

That's a good one---does your wife know?:

 

[dglez1]

Don't know what to report. Have had my 2007 GMC since Nov. 3rd (4500+ miles) and have had all kinds of mpg readings (hand calc). Have had as high as 17.92 mpg with 80% highway @ 70-75 mph. Had a recent check of 17.12 mpg with mixed 50/50 miles and then next tank under same 50/50 miles got 14.54 mpg. I'm confussed.
Pulled my 20' bass boat 150 miles one way with max speed of 75 mph and average around 65 mph, no wind, and 10% town conditions and ended up with 11.57 mpg. Not good. Filled up at start of return trip, max speed of 72 mph, average with cruise at 65 mph, 15 mph side wind and same 10% town conditions and ended up with a increase to 13.1 mpg. All of trip done with Hypertech stage 1 programed in. When I arrived home I decided to step up to stage 2. When DTC's were checked it showed a U1016 code with no CEL on. Cleared code. Truck ran great to and from. In the past I have recorded 14.5 to 15.5 mpg pulling the boat and 15.5 to 18 mpg without load. I just would like some consistency.
Is it the ULS Diesel we use now or is there a problem with my Duramax?

 

[tbalt]

I have a 06 LLY with 10000 miles and last weekend drove from Northern Illinois to Tennesse and got a consistant 20 mpg on winter blend. On the way back I had a 800 lb atv in the rear and strong headwind and averaged 17.5 mpg. Driving on the way down was 65-70 mph. The way back was pretty much the same but very windy.

 

[truckie481]

After 21,300 I am getting 18 mpg, I was getting 20 mpg before ULSD. I still get excited when I start her up in the morning and I cant wait to get back to her all day/night long, please don't tell my wife. :angel:

 

[a bear]

I think you have a winner.....17.12 is way better than I got for the first 10K or so. I'm now getting about 19.8. I don't get to check mileage very often since it's seldom ran without a load but I'm really pleased with towing MPG. 12-13 MPG in the 10-12K range and about 10-12 MPG in the 14-17K range. Most towing at about 65 MPH. Any tows larger than this are mostly short distance and were never checked.
The key to good mileage when towing is to watch your speed. There's plenty time to play when the truck is empty.

 

[mbs]

i just filled up for first time. went 400 miles from full to a click below a quater . i was actually impressed. 4 door,dual wheel. utility bed. lot of truck to drag around.

 

[SouthernGrey]

I have been getting in the 17's with 70% HWAY and 30% city, seems to be alot better (20-21) if all HWAY under 70, I am pleased.

 

[coldLBZ]

When I first got my truck I got 10 mpg as per the DIC. After the first fill, and the Power Pup I was getting a consistent 19 mpg hand calculated. At about 5000 km I went to the Performance setting on the Power Pup and I got 21-23 mpg hand calculated. This was 90% highway going to and from work. Over the winter I have gone down to about 17 mpg with the long warm ups, and idleing.

 

[thejdman04]

Thats great milage compared to what Im seeing.