2001-early 2004 LB7 Duramax Fuel Economy Poll

[Olden_B]

I have been amazed by those who post that they are getting better than 15MPG highway or other. I currently own two 6600 durmax's 2004 models, in silverado package Z-71 4X4 crew cab/short box 2500. Both have recently been put through the 30,000 mi program, at a cost of $700 per vehicle. NEITHER of my trucks which are almost exclusively driven on the highway get better than 13.5 almost always 12mpg. with cruise control on at 70. Does anybody have a clue why they are both getting such poor fuel economy. My local dealer has put them both on the computer, replaced the fuel regulator on one and the injectors on the other and still there has been no improvement, and an actual reduction in performance of the other. HELP??
Thanks!
Bill

Originally posted by More Power:
Fuel economy is one of the top 2-3 reasons why most people buy a diesel pickup.

What we want to do here is help determine what people are seeing for non-towing fuel economy in actual on-road use.

Let us know what your truck delivers.... This poll is for owners of the LB7 (2001-early 2004 model Duramax 6600 engines). We are assuming summer blend fuel.

You will need to vote before viewing the poll data. If you don't own an LB7, but would like to see the poll data, you'll need to first vote in the poll using the "Don't Own an LB7" selection for both the local driving and highway driving sections.

Round your fuel economy averages to the nearest whole number. For example a 16.4-mpg would be 16, a 16.8-mpg would be 17.

MP

[Driveshaft]

I Got My Problem Solved And Now Am Able To Login. Thanks.

[ricksofla]

2005 Ford E250 van 5.4 liter, 85,000 miles, 11/12 mpg, 2002 Chev. 3500 LT crew cab, 4x4 dually, 317000 miles - 17 / 18 mpg. priceless!!!

[Dustdevil1]

I often pull a trailer weighing around 10k lbs. Under those conditions, I typically see 10mpg while climbing from sea level to the Mojave Desert (around 2800 ft). 16 mpg on the way home. 13 mpg on flat freeway.

Without the trailer, I see about 16 combined, and about 21 on the highway. But I usually drive past 70 mph. Fuel mileage varies dramatically with rpm on my truck. I would imagine it does with all of them. I have 3.73:1 axles, and it's a 4X4 with oversized tires. I'm sure that has a little something to do with it. Plus, I don't often specifically drive for fuel mileage.