Tuesday, February 27, 2024
First Reviews 2020 GMC Sierra HD First Drive Review: Towing Anxiety Therapy

2020 GMC Sierra HD First Drive Review: Towing Anxiety Therapy

We had the chance to try the new 2020 GMC Sierra HD with the 6.6-litre V8 Duramax diesel engine. Here’s what we think.

The war between Heavy-duty pickup trucks is a never-ending thing. And with the 2020 GMC Sierra HD topping the charts in terms of towing capacity at 35 500 lbs, it was inevitable that we had to investigate and see how this truck handles loads, but also how it handles everyday life when It’s not on the job.

Statistically, only 50% of all HD truck owners tow more than 8 000 lbs. But all of them spend a lot of time in their truck. Either way, focus groups and surveys revealed that regardless of the size of the load, towing makes people very nervous. Thus, an impressive amount of towing tech was added in the GMC Sierra HD to make the driver’s (and everyone around) life easier.

A heck of a draft horse

2020 GMC Sierra HD | Photo: Louis-Philippe Dube

The 2020 GMC Sierra HD is available with the 6.6-litre V8 Duramax diesel engine that outputs 445 horsepower and an impressive 910 lb-ft of torque. It is paired for the first time with a 10-Speed Allison transmission that, according to GMC, dished out every foot-pound of torque in first gear for better accelerations.  With 35 500 pounds, it represents 52% more towing capacity than the outgoing Sierra HD. It was stickered at 9,750$ option on the Sierra 2500 Denali we tested.

The base gas engine in the 2020 Sierra HD is a 6.6-litre V8 that delivers 401 horsepower and 464 lb-ft paired with a 6-speed automatic trans that enables it to *only* 17 400 pounds.

Interiors to (not) die for

2020 GMC Sierra HD | Photo: GMC

Twenty years ago, HD truck customers would’ve told you that a truck is made for workin’ and not for comfort. Today, the game has changed. Competition is fierce and basic interiors in a 70k$+ truck don’t cut it anymore. Think about it, HD haulers are often purchased to tow a 20 000-pound luxury camper trailer with 20k countertops finished in quartz. Needless to say, a certain level of interior finishing is expected.

For the 2020 GMC Sierra HD, that’s unfortunately not the case, even with the Denali trim sporting too much plastic, and seats that offer minimal comfort. The AT4, although stylish-er, isn’t up to par with the segment, especially Ram’s offering in that department.

That being said, the people at GMC confirmed that next-generation HD pickup trucks will have swankier interiors, and they were very serious about it, so maybe this detail won’t be a problem for long.

Otherwise, the cabin is huge, with first-class legroom for the passengers in the rear. Functionality is there, with an available 15-camera views including the industry-first transparent trailer view and a rear Camera Mirror. A key part of the therapy, the transparent trailer view can undoubtedly alleviate stress, making the trailer less of a big thing on the road.

On the road with the 2020 GMC Sierra HD

2020 GMC Sierra HD | Photo: Louis-Philippe Dube

Driving a heavy-duty pick up truck without a load still constitutes an experience in its own. And the 2020 Sierra 2500 Denali blended well in Jackson Hole, Wyoming, where every county could be called Ranch County. Bottom-end torque is more than ample, thanks to our friend Allison who is surgically reactive and makes an excellent team with the Duramax engine. Ride comfort is on par as well as steering – even around tight corners. Visibility is tricky – this truck is as boxy as it gets, so relying on camera systems at tall times even when not towing is wise.

Further down the road, GMC pinned a load of upwards of 30 000 pounds on a Sierra 3500 Dually for us to feel some pressure. Back on the road with our load weighing as much as a small house, accelerations were very impressive from 0-100 km/h off the line. Ride comfort was only slightly impacted, with a more “nervous” front-end when fully loaded. This symptom will probably never manifest itself with a load below 10k. Braking was phenomenal is all cases – which is a key safety factor when hauling any kind of load.

The MultiPro tailgate was a pretty neat feature too. Available on all trims it is configurable (6-way) and splits into different configurations.

The AT4, when you want the gear without the bling

2020 GMC Sierra HD | Photo: Louis-Philippe Dube

Outfitting a capable pickup truck has always come with one huge issue. If you want all the tech, it usually comes with all the chrome. But chrome isn’t everybody’s cup of tea. We also spent some time in the Sierra HD’s newest addition to the family, that might help put this problem to rest

Available on all Sierras and Acadias – and coming soon for the Canyon, as we just learned, this trim, which squeezes between the SLT and the Denali not only comes well-equipped for the working individual who wants comforts and technology, but it also sports a more contemporary kind of luxury, which is composed of blacked out, assorted colours instead of shiny ones. It is more discreet, but you can still definitely tell it apart from the other trucks.

AT4’d Sierra HDs also feature mechanical bits like an off-road suspension with Rancho Shocks, skid plates and locking rear differential, increased ground clearance of over 10 inches, an off-road mode, Hill Descent Control and Hill Start Assist.


2020 GMC Sierra HD | Photo: Louis-Philippe Dube

There’s always a new “The King Of The Hill” in the large pickup truck segment. Ram HD has the torque number with 1000 lb-ft, GMC Sierra HD has the tow ratings, and the Ford F-Series Super Duty scheduled for a major overhaul… anything can happen from now on. But for an driver that needs to tow heavy loads, work all day in the cabin and be comfortable when he or she’s not doing either or, the 2020 GMC Sierra HD is right on track– and if the interiors can follow, the Sierra HD will have a serious edge in the battle.

2020 GMC Sierra HD Photo Gallery

2020 GMC Sierra HD | Photo: GMC

2020 GMC Sierra HD | Photo: Louis-Philippe Dube

2020 GMC Sierra HD | Photo: Louis-Philippe Dube

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Louis-Philippe Dubé
Louis-Philippe Dubé has been contributing at MotorIllustrated.com for over a year, and for the NetMedia360 network for nearly three years now. His passion for everything automotive comes from a career as a mechanic, but also from the family vehicle collection that includes a 996 Porsche Turbo and a 2004 Ford GT. We've been bugging him to drive the GT, but he hasn't responded. Send L-P an email


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