I had a big ‘ol manly Texas truck this week, the 2012 GMC Sierra Denali 2500 4×4 with the Duramax diesel and 6-speed automatic transmission. I can’t say I enjoy driving any three-quarter ton or larger truck, they are just so big and ride so rough, but I get so many questions on them, I just have to do it.
For those that need to tow or haul heavy loads, this truck is a contender. This Sierra Denali came completely loaded with everything you can think of including the navigation system, a power sunroof, heated and cooled leather seats, rear camera, 20” aluminum wheels, chrome running boards, and even a heated steering wheel.
The Duramax performs well and the 397-horse 6.6-liter turbo diesel is quieter than I remember it from past experience. The Allison transmission is smooth and changes fluidly, unlike the last Ram I had which seemed to slam into the various gears. From a dead stop, the 765 lb-ft of torque will get this mammoth truck rolling quickly and deliberately.
For those of you who tow, the Sierra Denali has impressive numbers. For a conventional towing setup, you can pull 17,000 pounds and if your trailer is a 5th wheel, it goes up to 21,700 pounds. That edges out the Ford F250 by a scant 100 pounds and slays the Ram HD which is rated at 17,000 pounds with a 5th wheel setup.
Also for folks who tow, stability control, trailer sway control, and diesel exhaust brake are standard, and an integrated trailer brake controller is available as an option.
The interior of the truck is very nice, the seats are comfortable, and everything is super easy to operate. This truck has a large amount of interior cubby holes and numerous cup holders for all occupants.
As is typical of any truck this size, the ride when not towing is rough and you feel every bump in the road. It just has to be this way to have a truck that can tow 10 ½ tons. I think the GM fully-boxed steel frame makes this truck stiff and rigid, but at the same time very stable. The independent front suspension on this truck gives it responsive steering for a truck of its size.
In the ongoing battle between diesel trucks, I think the Ford Super Duty holds an advantage in quietness, fuel economy, and without a doubt in back seat room-which is a little cramped in the General Motors entries.
Speaking of fuel economy, the Denali got 15 consistently in town and with the 3:73 rear-end this truck has, I got 20 miles per gallon highway at 65-miles per hour.
I’ll let you truckers go out back and argue which is best between the Duramax, the Powerstroke, and the Cummins.
I can tell you the GMC Sierra Denali 2500 diesel is a very capable truck.
What I liked most: The torque and quietness of the Duramax.
What I would change: For sure, more back seat room.
Fuel Economy: 15 in town, 20 on the highway.
2012 GMC Sierra 2500 in a few words: A very capable truck with impressive stats.
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