PorscheDoc

2500HD 4x4 6.0L Gas:

Sitting in the driveway: 14
Around town: 14
Highway @ 80: 14
Towing open steel trailer @ 80 : 14
Coasting down a hill: 14
Climbing a mountain: 14

RickBetterley

17 empty, but 10-11 mpg towing (2008 F-250 diesel crew cab w/short bed pulling 2500 lb enclosed CargoPro (nee Thule) trailer + 3500 lbs. or so of car and spares) around 70 mph.
By the way, saw an SUV and trailer camper upside down on Rt 495 near Westford MA Saturday; reminded me of why I like substantial tow vehicles.

Chaos

96 Yukon with a RV cam 350. 12mpg,9-10 mpg towing.

DogInBlack

GMC 2500 HD Duramax Crew cab short box-
Around rural Lower Alabama- 20.3
Interstate empty at 75- 19.1
Towing Haulmark 20' at 70 flat terrain- 12.8-13.1
Towing Haulmark 20' at 75 varied- 11.0-12.0

All stock, but curious about a chip or a line on a nose cone to save mileage.

Mike Buck

4x4 Tundra Double Cab 6.5' bed, with 5.7L & 6spd auto

19-20mpg - 75mph highway, unloaded. That is right at about 2k rpms in 6th.

13-14mpg - 70mph towing on highway going to VIR. Going to Watkins Glen I didn't get this mileage, it it was more like 11-12mpg. Open Trailex with 8 tires on rack and 3100lb car. Another 1000lbs in bed and back seat of truck. In tow mode I usually keep in 5th unless it is really flat and then I use 6th. Such a better tow vehicle than my 1500 Ram. Gearbox is major reason. Sequential console shifter ftw.

At the drag strip, this truck will beat my car in the 1/4 all day long. Very fast for a bone stock truck

KOAN

4x4 Tundra Crew Cab 6.5 ft bed 5.7L and 6 spd auto get 18-19 unloaded 75 mph
Pulling 24 ft enclosed PACE and GT3, tools, tires, etc approx #9500 get 8.9 mpg 65-70 mph. hilly or flat.

I'd like to get a bubble. Anyone have any data and a source?

Gary R.

06 Duramax 3/4T Silverado towing a 24' V-Nose Thule aluminum - 12-13MPG at 75MPH (avg), 17-19 avg without.

TRAKCAR

Mine can not even hold speed with cruise control at 80+ it drops to 75 , kicks down to 3000 and goes to 85 and so on and so on... I try to go downhill fast, 90+ so it does not drop down a gear on the way up, I can not keep the pedal down below 75, or it will down shift.

I had a 7.3 before chipped, my mechanic adviced, no problem. Still running with 240K miles, but my mechanic says don't touch 6.0, very bad things will happen.

The MPG are all over, but big factor is speed and wind resistance, in California speed limit with trailer is 55 and rearely any truck goes faster when i was there. I told Optima, I will pay whatever for tapered nose and bubble, they refused and I cancelled. Than they build it. I also have 1' extra height, the trailer is about 7'4" inside. Wings do not work at all, but the bubbles really do work.

Here in Florida I go 90MPH and still getting passed by trailers.
The truck is governed at 94MPH and sometimes I try to draft behind a train and can't stay with them....

analogmike

I have a lightweight trailex trailer and my V8 Touareg is usually in single digits towing, not much more around town without towing.

I had a Grand Cherokee with the 318 V8 and I could eke 15MPG towing at 65 or so if I was gentle and used hills to my advantage. Durango with newer small V8 was not nearly as good as the old fashioned Jeep engine.

d15b7

yikes! your 8.1 is thirsty!

mine is a 2003 2500HD 4WD extra cab with long bed. 4.10 gears, with the 8.1 Allison. i have a performance/towing chip in it, tuned for 91 octane. (but i only run 87 octane, combined with my own designed water injection system. works great!). empty at 70 mph cruising i get around 13-14 mpg. with my 20' enclosed Pace and loaded (9k lbs or so) i get 9-10 mpg at 70 mph. i've never, ever seen worse than 8.xx mpg, even towing at 80+ in the big hills (heading to the Glen).

as an aside, my previous truck was a Ford 3/4 ton with the 351W and towing package (3.55 gears). towing the same trailer and load, it would get around 6-7 mpg at 70 mph (and it couldn't really average much faster than that; she was WORKING SUPER HARD at 70+ on the grades). i think the big block chevy is hardly working, and as such seems to get much better gas mileage when towing..... (the ford would get 16-18 unloaded with no trailer on the highway when cruising).

todd
ReidSpeed

NJ-GT

Hummer H2, Featherlite 18' open trailer, 3,000 lbs Fiat on top. 8.6 mpg GPS/Gas receipt verified.

10.4 mpg not hauling.

Veloce Raptor

8.1 GM gas, especially the 2005 & 2006 versions, is a superb motor. It is a real tragedy it was discontinued at the end of the 2006 model year for emissions reasons.





Professional Racing and Driving Coach

GT3 Nut

I have found similar:
2008 GMC 2500 HD Duramax Crew Cab Short Box- (Truck has approx. 17,000 miles and it has 33"x11" Nitto AT Tires)
Highway @65 20+
Highway @75 18+
Towing 32' Featherlite Gooseneck (loaded weight about 12,000 pounds) 12-13mpg (from VA to Sebring)

New Tow Vehicle:
2009 GMC 3500HD Crew Cab Dually- (Under 3000 miles)
Highway @75 15+
Towing 32' Featherlite Gooseneck (loaded weight about 12,000 pounds) 9-10 mpg (from NC to Watkins Glen)
I expect that the 3500HD will improve with some mileage but will not quite be as good as the 2500HD because of the added width of the dual wheels.

Spec944 #143

06 Nissan Titan 5.6 liter with a cab high shell and 20' enclosed haulmark trailer. I get any where from 5 to 11 mph towing. The 8-9 is the normal while the 5 was heading to las vegas from salt lake city in a winter storm in february. There was 40 mile an hour head wind almost the entire way. I kept it speed at 65-70 but it was in 3rd gear at 4500 rpm much of the time

The truck tows great as I often have large "hills" to over here in Utah. she has little issues with them.

007DT

I just towed to VIR 330 miles and got 10.9 there 11.3 back? According to the computer onboard.

Do you have the air suspension?