I have very little knowledge of the Duramax trucks and found a used one that I am looking at. It's a 2005 GMC 2500HD 6.6l turbo w/ allison tranny. I searched around but couldn't find any specific numbers and answers that I was looking for. What kind of mileage can I expect with this? Also, what hp and tq numbers do these put out? Anything specific about the 05's that I should be aware of? I currently have and 03 Z71 but need something to pull my car with so that's why I'm looking at this. It's priced at 31,9 w/ 54000 miles. That seems a little high from what KBB said but I think I can get them down some. Anyway, I would just like some guidance since I have never owned a diesel. Thanks.

 

You can expect some really nice milage out of a duramax. I just had one as a loaner truck while mine was getting some tuning done. It had a very light tune from diablosport in it an it was getting 15-16 in the city with me beating on it pretty hard. You could baby it and get more im sure. It was a crew cab 2wd. Im not sure what the HP and tq numbers are though, but the dmax is usually faster than a similar prepped dodge or ford.

 

The Duramax your looking at has the LLY Diesel, A great engine and is making sick power in a lot of guys rides. Tuning/exhaust tranny upgrades will net you 12's or lower I have 3 close friends with Duramax trucks, 2 of em have 20,000 miles and get 20MPG with just a Hypertech programmer, myself and my other buddie get 16-17 but our trucks are breaking in still, Its too hard to go putting around with all this damn torque! It sound like the price is a tick high but if its in good shape im sure its worth it. I believe your LLY puts out about 310 HP and 590 tq or real close to that. You just have a little more maintainance with a diesel, -Fuel filter changes, oil ( ten qts) and a spin on filter for the allison, no big deal. GO FOR IT!!!!

 

my dads gets 15mpg with mixed( loaded and unloaded)

my dads 04 ccsb 4x4 white D/A was 30k out the door

 

Thanks guys. The allison is a 5 spd auto right? (I haven't driven it yet. I just had my wife go by and look at it.) Also, is the rear a 4.10 ratio?

 

I've never heard of the 4.10's with the allison, don't even think you could get it. In the glove box there is an engine code sticker with all of the options it has. GT4 = 3.73 GT5 = 4.10

 

it depends on the trans the later ones are 6-speed

 

Yes, its a 5 speed Allison, 6 speed Allie came out in 06 models. 3.73 with the Allie/ Duramax. 4.10's come with an 8.1 gasser as an option.

 

Well thanks for all the help guys. I picked up this '07 last week. Got them to throw in a bedliner, tint the windows, a pinstripe, and upgrade to some 285's.

 

Hell yeah! Sweet truck! Are those factory seats? the inserts look great. Sounds like you drive a hard bargain!