I've got a Ford 6.0L PSD. I haven't had any problems w/mine except for a sensor that needed to be replaced around a year ago and a reflash.

I know a fella that has an '03 DMax for sale that I might be able to get at a good price. I like how comfortable the GMC is and how quiet the DMax engine is. I test drove his truck and I don't think it has as much power as my 6.0L, but I can live with that.

The owner stated that he gets around 21 MPG on the highway while drving 70-75 MPH?! Is that true? The best that I've ever gotten is 18.5 MPG on my 6.0L.

What do you fellas think about your trucks? How is the Alison tranny? Would you buy another DMax? Any tips/suggestions would be appreciated:grd: .

The best I've ever gotten on the highway was 19.66mpg. Average I would say is 18-18.5 highway and 16-17.5 on country roads and that's using Stanadyne additive. Would I buy another DMax? Yes I would.

I Think The Milage Is High

I Think The Milage Is High
I don't, as I regularly see 20 mpg at highway speeds. If you slow it down to 55-60 on the highway, you can even squeeze a couple more mpg outta these engines.

I haven't squeezed that good of mileage out of my truck but I have seen 19mpg on road trips. I have a hard time staying out of the throttle;)

on edit Yes I wouldn't buy anything but another DMax , but I don't like the others styling(and thats just my opinion)

As good as my fuel mileage is, I would have to say the mileage he claims to very high. 21 mpg average is not possible at those speeds. I have seen 22.3 max one time @ 65. And I can get 20-21 @ 62-65 mph, but when I drive 70-75 it drops down to 18.8-19.3. But my average running empty is more like 18.9. I did get 19+ @ 72 mph on the 540 mile round trip to Indy last month.

If you have one of the good 6.oh no`s then I would keep it. They are very nice trucks. As for buying a Duramax again. IN A HEART BEAT! It is by far the best truck (Vehicle) I have ever owned/rode in/drove.

If you need/want more power, it is just a program away for either truck, and you won't believe the difference!

I'd buy another Dmax/Allison. The fuel mileage seems high.

I went from a Ford Stroker to my GMC 2500HD. The MPGs are on the high side, unless the guy drives 55. About the truck, at first I had to get use to the cab. Not as much room as the Ford. The only thing that still ticks me off is the wheel/tire set-up 245s out of the box and the wheels are only 6.5" wide, zero room for tire upgades.

The Duramax and Allison is a GREAT combo! I am not even thinking about my next truck, because I love this one so much.

Good Luck

I've got a Ford 6.0L PSD. I haven't had any problems w/mine except for a sensor that needed to be replaced around a year ago and a reflash.

I know a fella that has an '03 DMax for sale that I might be able to get at a good price. I like how comfortable the GMC is and how quiet the DMax engine is. I test drove his truck and I don't think it has as much power as my 6.0L, but I can live with that.

The owner stated that he gets around 21 MPG on the highway while drving 70-75 MPH?! Is that true? The best that I've ever gotten is 18.5 MPG on my 6.0L.

What do you fellas think about your trucks? How is the Alison tranny? Would you buy another DMax? Any tips/suggestions would be appreciated:grd: .

:welcome2: Welcome to the board. It's my opinion that if either Ford or Dodge could offer an automatic that's only half as good as the Allison, they might, maybe, might get a few more converts. The Duramax w/Allison is pretty hard to beat. I've gotten 21mpg on trips running 65mph on cruise with no A/C, but lesser numbers are more the norm for me. Buy another? Only if I wear this one out!

I don't know about the LB7, but my LLY has gotten 21mpg several times at 72mph, hand calculated.

I get 21 on the highway at 70-72mph. Truck is 2wd I believe that helps a LITTLE.

Best I've seen on my 2002 D/A CC 4x4 is 19.9 when kept around 2000 rpm's or ~70 mph. Usually get 16.0 City/18.5 hwy

Milage is a relative thing for any engine. I have gotten over 21 mpg driving 73 mph on the interstate. However, there was a 20 mph wind helping me along. Driving back into it I only got 19 mpg. Thats according to the computer on the truck. It has averaged 17.7 in 35000 miles, again according to the computer. BUT when I go to town it 40 miles to the closest big town with 45 and 60 miles away being the other choices so I spend a lot of time on cruise control. I do not do that much towing unless going to the lake with the boat or dragging the car trailer around every now and then. I have had no injector problems, I'm not juiced, I do not notice a lack of power anywhere and I can damn near keep up with the wife's cadillac through the quarter mile. Not bad for a 7000 pound truck. I would buy another one but I don't have any reason to get rid of this one.

03 cc sb 4x4 d/a

21mpg is fairly normal.

The old duramaxes dont have as much as the new 6.0's but if you hang out here much that can easily be fixed:muahaha:

Love my max. I average 15-16 MPG hand calculated each tank. I've gotten a best of 18 per tank before(I was late to a drag race and rolling down the interstate) but ussually 15-16. Worse of 12 for a tank while plowing. I drive rather "spirited" and ussually there is a trip to the 1/4 or at least the local hang out for a few street races. Never been able to keep my foor outa it for 400 miles to get an idea of what a normal person would get:lol:

Love my truck!

One of these days I'm going to have to top here off and check my interstate milage while drivng normaly.......

Well hopefully you don't overheat the max on the way home from the dealer, and after a month of using it it won't need a new set of injectors, yea, I'd buy another Dmax.....

The best I got with my 03' was 20.1 mpg, this was when I filled up in West Virginia, on my way to Myrtle Beach. Filled up again after 462 miles in Myrtle Beach. My avg MPH per the DIC was 55. Took a different route coming back with an avg MPH of 60 I only got 18.4 mpg. A little more mountain driving on the way home.

Best my truck has gotten was my brother driving it for a tank and being careful because it was my truck ):h. It was mostly 2 lane driving w/an average speed of 55/65 and my Edge set on level 1 or 2 (not sure which). His tank came in a tick over 20 mpg (hand calculated). My personal best was my very first tank @ 17.6 mpg, country driving.

The only trip I've had it on was a 4,000 mile round trip from Indiana to Idaho and back. Was towing a car hauler with 2 cargo trailers and my 1/2 ton pickup for a total wt. of 22,500 lb on way out and a VW Bug and parts of 3 Ford trucks on the way back weighed in @ 29,200.
Best fuel mileage 9.8 and the worst just a shade under 7. :muahaha: