04 Duramax 2500

[Maysdave]

I am looking at maybe getting a 04 duramax 2500 to pull my 28ft travel trailer. The tt weighs 4800 lbs. any body have any guess of what kind of fuel mileage I may see with this setup.

[450Donn]

My 04 4X4 ext cab scaled ready to go at 7500 pounds generally got 11 towing and usually got 18-19 non towing highway mileage. Just be aware the LLY was a short lived version and was probably the worst Duramax made. Many of then had overheating issues. That problem can be fixed for a price though. Personally I would look at late 05 LBZ or newer.

[Oilbrnr]

Originally Posted by 450Donn

My 04 4X4 ext cab scaled ready to go at 7500 pounds generally got 11 towing and usually got 18-19 non towing highway mileage. Just be aware the LLY was a short lived version and was probably the worst Duramax made. Many of then had overheating issues. That problem can be fixed for a price though. Personally I would look at late 05 LBZ or newer.

The problem isn't the engine with the LLY, it is the cooling system, specifically the size of the radiator, air intake and the fan. I was on the forefront of this issue back in '05 with a guy out of TX. They can be bandaided, but I agree, look for a LBZ+.

Regardless of the drivetrain, the remainder of the GM product 11 years and 117k later, is also disappointing. Time has come to sell my '05. Actually trade, as I'll probably make out better (or easier) than dealing with a private knowledgeable buyer.

To your mileage question, figure 10-12.

[Mtn.Mike]

Just to clarify, the early 04's had the LB7(That's what I have) and they are prone to injector failure.
I've put 3 sets in since I've had the vehicle.
I've also towed a bigger trailer than you have and gotten around 12 mpg.
Without towing I get 17.5 mpg driving in the mountains of Northern Pa.


Mike

[Maysdave]

Wow. Thanks a lot. I may be better off keeping my 07 classic 1500 HD 6.0L then.

[KD4UPL]

Despite what some have said the '04 Duramax is not necessarily the "worst Duramax". A mid year engine change occurred in '04. The early trucks with a 1 in the 8th place of the VIN had the LB7. They had injector problems and should be avoided. These would be the "worst" duramax engines. Latter '04 trucks had the LLY Duramax. These have a 2 in the 8th place of the VIN. Some of these trucks had overheating issues. Others didn't. My own LLY does not overheat and has been a great truck.
Also, despite some previous posts, the LBZ was not available in '05. It became available in '06 and into '07 where another mid-year change occurred. The LBZ is by far the best Duramax.
If this '04 has the LLY I wouldn't be afraid of it.

[chertz]

I think the OP asked about fuel mileage with this setup...

I can tell you when I had my 2005 Cummins, towing a 30' TT (weighed around 7k) on longer trips down the highway it would average 13ish... I would assume the duramax would do close to the same maybe?