This is my first post so be nice. First of all, I do know how to calculate the fuel economy of my truck. Have records of all vehicle going back 15 years. I bought my truck the middle of september 2004 and currently have 23,000 miles. Have had the predator on the truck in various tunes since 6000 miles. I have decided I like the 100 horse tune the best and that is where it has been for the last 5500 miles. I currently average 17 mpg in mixed driving 75% highway 25% city. I have towed lightly on several occasions, up to 5500 lbs and never got less than 14mpg.

I had to make a run to Utah so I decided to see what the truck would do. I loaded my dad's 6.2 diesel 4X4 suburan that came off the scales at 7300 lbs onto the open car hauler for a total weight of 9340 lbs being towed. My truck tips the scales at 7130 lbs. The route for those familiar was from Shoshone, Id to Ogden, Ut via I-84 and I-15. There are three decent hills. I have no idea on the % grade but they are all about 1.5 miles in length. On the way down I set the cruise at 76 mph and on the way back it was set at 66mph. Predator was left on 100hp.

On the way down the truck never down shifted, and maintained 76 mph with ease. EGT's averaged 1000 to 1100 while cruising with boost always around 5-7 psi. On the 3 hills EGT's usually maxed around 1350 with a couple of brief 1400-1450's. Boost never went over 18 psi. Total distance with trailer was 212 miles. Fuel economy was 10.8 mpg.

On the way back the truck never down shifted, and maintained 66 mph the entire time. The hills are a little longer on the way back and not quite as steep. EGT's averaged 850 to 950 while cruising with boost always around 5-6 psi. On the three hills EGT's maxed at 1350 again with one brief stint at 1400. Boost never went over 16 psi. Total distance with trailer was 197 miles. Fuel economy was 12.6 mpg.

I was extremely impressed with the towing ability of the truck. I came from a 98 dodge dakota with a 318 and 5-speed. It averaged 9 mpg pulling my 6000 lb travel trailer and struggled to maintain 65 mph in fourth.
Just have to say thanks to the better half for finally letting me get my Duramax. It only took 5 years, but it was definitely worth the wait.

Good write up. Thanks!

Your mileage data is about the same as mine. On a 5000+ mile journey towing at a combined weight of just over 17,000lb, it averaged 11.5mpg mostly going 75mph, and running the TTS Tow.

Just have to say thanks to the better half for finally letting me get my Duramax. It only took 5 years, but it was definitely worth the wait.

A mans got to do what a mans got to do to get his truck! :hail: :naughty: :smoke2: JJ <!-- / message --><!-- sig -->

Took my Duramax on it's first real long distance towing experience this last weekend, Ft. Worth TX.to Santa Fe NM and back. 630 miles each way. We were towing a 8000lb bumper pull travel trailer. I was running the Predator on it's 40 HP setting and hoping to see a big difference in the pulling power. Well it did make a big difference. So much so that a few time I forgot that I was pulling the trailer and had some close calls when my attention wandered. It pulled so smoothly and responded so quickly it was awsome. My mileage hand calculated was 12.4 MPG average down and back. My question is, is does this mileage seem low as compared to the light weight that I was towing? :confused:

I havent towed with my 02 yet but i took it to Kansas City Mo from Richmond VA approx 2000 miles. On the way there i kept it 5 mph above the speed limit and got 16mpg. On the way back i kept it below 70 mph no matter what the speed limit and got 21. Truck never downshifted either way. Upgrades are 4" Bully Dog exhaust and the Bully Dog Power Pup set at 70hp.

Forgot to add that I went the speed limit 70-75 both ways.

Moakster, at that speed I think your mileage is in line. If you slowed down to 60-65 your mileage would probably jump to 14mpg or better. ;)

Thanks Vsouth, just wondering..

I came back from a trip last week and was very dissapointed in my milage. I have an 05 that had 500 miles on it when the trip began. Total distance was 1907 miles and I averaged just over 7 MPG. I was towing a v-nose snowmobile trailer that had a loaded weight of around 8500-9000 lbs and had 4 200+ lb men and 100-200 lbs of gear each (tools, oil, clothes, beer.) I verified my tire correction of the Predator with GPS and it was off by less than .5 MPH. I had the 40 tune installed and hand calculated all of the milage. My DIC showed an 9 MPG ave. I wish!! Trip was from Eastern Iowa to SE Wyoming.

Vsouth, my mileage is real close to your on the exact route. I made many trips to the Jerome shooting range pulling my 10K 5th wheel. The steepest hill is Rattlesnake 25 miles west of Tremonton. I pull it both ways in 5th gear also. My towing average is 12.1 for a little over 11K. Later! Frank

my dad going to michigan with 4 snowmobiles on a bumper pull steel trailer and got 8mpg on his lb7 stock but there happened to be a lot of idiot drivers in the fast lane that wanted to run the same speed as those in the slow lane so the throttle seen a fair amount of full throttle when going around dumb _ss drivers. there was no chip this was stock.

I did about 3200 miles worth of towing last week. Went from MA to Bowling Green, KY to pick up a C6 convertible. Then to Panama City Beach for some Spring Break action and then back to MA. The truck was pulling a 24' enclosed car hauler that probably weighs about 6000lbs without a car in it. Truck had 2300 miles on the odometer when I left.

Mileage really wasn't what I expected it to be. The best that I saw before loading the car was 11.3 and the best after adding the extra 3200lbs was 10.2. I don't tow like Grandma so that probably has something to do with it. I tried a few different settings with the Edge and found that level 3 gave me the best mileages. Didn't try that one with the car inside. Only went to level 2.

Here is a rundown from the notes that I was keeping -

Hauler with no car -

10 MPG - level 2 tune - running between 65-75 - some slow driving because of traffic/snow
9.1 MPG - level 1 tune - 70-80 MPH - getting into the hills of PA
10.9 MPG - level 3 tune - about 70-75 MPH
11.3 MPG - level 3 tune - 70-75 MPH
8.9 - level 2 - running at about 80 MPH most of the time

There were a few other tanks of fuel. The numbers are pretty much the same.

After the car was loaded (level 2 tune unless noted) -

9.0 MPG - 75-80 MPH
8.6 MPG - cruise set at 80 MPH 95% of the time
8.9 MPG - 80-85 MPH
9.6 MPG - 70-75 MPH
10.2 MPG - 70-75 MPH with the level 1 tune

I believe the RPMs were at about 2300 while doing about 75 MPH and 2500 or so at 80. I know that I can't expect the world at these speeds but I did exect a little higher. Especially while cruising at 70-75 MPH. I was thinking at least a solid 12-13.

All of the numbers above were calculated by hand and the tank was filled to the rim each time. I found the display to be off by about .5-.7 MPG (reads high) and the fuel used was off by about 2 gallons when it was time to stop (reads low).

I never saw the low fuel light at any point. The most I needed was 29 gallons. Does anyone know what point that comes on? I'd be very happy with a solid 12 MPG but I expected at least 13. My father-in-law has a Dodge that gives him mid to high teens with the same type of trailer/load.

The truck towed with no problems at all. Didn't need to downshift at all. As my buddy said "this thing just goes!".

I pulled a 24' enclosed car trailer with a c-5 vette from tulsa, ok to boston, ma. These 26 gallon fuel tanks do net let you go near far enough between fill ups when pulling a load. I averaged 10mpg at 75mph. The trailer and car weigh around 4 tons I guess. But the stock lb7 would pull up those big hills in the northeast like the other trucks are sitting still. The fun part is getting in the fast lane when the signs say slow moving vehicles stay in the right lane. I guess they were talking to the dodge and ford guys, because that is who we kept passing!