No more towing blues with the 2021 Sierra 2500 Denali Duramax 6.6L Turbo Diesel


Experienced by Adrian McQueen

Photography by Adrenaline Lifestyles


Towing has become a routine part of my life whether it be moving motorcycles, tractor equipment, hauls to the dump or vehicles. This time around the mission was to pick up a 1973 Chevrolet Impala and trek it about 250 miles back to my home to begin the restoration process but those plans quickly changed once we learned that one of our work trucks broke down in that same area. Well, the good people at GMC delivered the 2021 Sierra 2500 Denali Duramax 6.6L Turbo Diesel to my doorstep right on time, because I could surely put it to task.  I mean that is the whole point of reviewing these vehicles. Putting them in practical situations and seeing if they meet your expectations.

General Motors Truck Company, or GMC, is owned by General Motors. General Motors is an American automaker known for pickup trucks and SUV’s. GMC is one of GM’s subsidiaries, along with Chevrolet, Buick and Cadillac. The GMC Denali nameplate was introduced with the GMC Yukon for the 1999 model and is now used by GMC for the “top of the line” trucks and SUVs. Vehicles with the Denali trim option are priced a bit higher than the other packaged models. There are a few notables about the “Denali” name. It was derived from the native Alaskan Athabaskans / Koyukon people’s name for the tallest mountain in North America. In addition to that, it is the name of the Denali National Park and Preserve that surrounds the mountain, along with the Denali State Park. This mountain was formerly named Mt. McKinley and officially renamed Denali in 2015 by President Obama’s administration.

Upon first look you notice the prominent GMC emblem on the chrome grill, as well as the chrome front recovery hooks. The Denali has LED reflector headlamps and LED fog lights. At night, the lights from the side-view mirrors illuminate very brightly, assisting in various tasks. In the rear the Denali has 6-way multi-pro – flip/fold/step-up tailgate, a new power-retractable assist step with LED perimeter lighting, right-hand and left-hand side bedside storage, gooseneck / 5th Wheel Prep Package and four tie-downs. The rear literally turns into a work surface or a bench. The Denali sits on 20” polished aluminum wheels.

The interior is plush, decked out with leather a heated and leather wrapped steering wheel, heated and ventilated front bucket seats, heated rear outer seats, like dark walnut and dark ash grey wood interior trim, power sunroof and a 60/40 rear folding bench seat with the storage package. There is a rearview auto-dimming mirror with partial video display. The new mirror shows the video feed of the cargo bed, captured by an equally-new Bed View Camera.

Our Sierra HD has the larger touchscreen infotainment system with Navigation, Apple CarPlay and Android Auto, a Bose audio system, SiriusXM satellite radio, a rear-seat entertainment system, a 120-volt outlet, a mobile hotspot, and additional charging ports. I had to keep reminding myself that this in indeed a work truck because it has all the features, that most of the luxury vehicles that I receive to review have in them.

My towing experience with the 2021 Sierra 2500 Denali Duramax 6.6L Turbo Diesel was definitely a step up from what I am accustomed to. The Sierra has a single-rear-wheel axle that is able to carry 3979 pounds of payload and 18,500 pounds of towing. For 2021, the heavy-duty Sierra receives a host of new or improved trailer-assistance features. The jack-knife alert is a trailer-length indicator that lets the driver know when nearby traffic is close to the connected trailer. The truck’s infotainment system allows users to store different trailer profiles to monitor maintenance. We used the guest profile for this experience. Once we loaded the Chevy Silverado F250 onto the trailer, the Sierra HD adjusted in height to level out the balance.

The camera system that features up to 15 different viewing modes, was extremely helpful. As we loaded the trailer, the camera activates in the Sierra HD to show you how the trailer is being hooked up. This a great safety feature and assisting the driver in the process. Engaging the turn signal activates a camera that goes the entire length of the trailer to that you can see all that is around you. There is also a “transparent” mode that allows the user to virtually see through an attached trailer as if it wasn’t there.

Towing back up Interstate 95 was a breeze. There was not any lag in accelerating and maneuvering through traffic. The reason for this is because the Sierra HD has a 6.6L V8 turbo-diesel Duramax engine coupled with the Allison 10-speed automatic transmission kicks out 445 horsepower and 910 pound-feet of torque. The Denali has 4 wheel drive with a 2 speed transfer case and an X31 off road suspension system with Rancho Shocks. The diesel powertrain is quick and smooth. Braking was relatively smooth and responsive as well. There is even a button to engage the exhaust brake aka the “Jake brake”.  Once we made it back to Maryland it was pretty dark. No worries, but the truck has lights in the rear, bed and side-view mirrors that literally light up the night. This truck passed the towing test with flying colors.

Fuel economy with the Sierra 2500HD diesel was far better than gas powered pickup trucks. Before towing we reached about 17 mpg on the highway. On the way back, towing the truck, we earned 13.2 mpg on the highway with the Sierra 2500HD Denali. Highway range on a full tank was around 600 miles.

The safety features added to the Sierra 2500HD are much needed with features such as  blind-spot monitoring, rear cross-traffic alert, lane-departure warning, trailer tire pressure monitor sensors, front and rear parking sensors, forward-collision warning and automated emergency braking.

GMC provides a competitive warranty plan for the Sierra with a limited warranty that covers three years or 36,000 miles, a powertrain warranty covers five years or 60,000 miles and complimentary maintenance that is covered for the first visit.

The GMC Sierra is in a highly competitive class going up against the Ford F-Series, Dodge Ram, Nissan Titan, Chevrolet Silverado and the Toyota Tundra. Heavy-duty pickup trucks such as this one are supposed to be workhorses rather than show stoppers, but the 2021 GMC Sierra 2500HD succeeds in both departments. The model that we tested is priced at $78,755.00. Overall, I really enjoyed the Sierra 2500HD. It can knock out the job that you throw at it and look good in the process. I can only imagine what the 3500HD will bring. Please enjoy my photo gallery.


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