Review update: The 2020 GMC Sierra 2500 AT4 innovates where it counts

March 5, 2020

The 2020 GMC Sierra 2500 Heavy Duty clocks in for the new decade with innovative new features that make life easier—and more enjoyable—at the job site. Getting around in general has also gotten easier in the redesigned work horse.

For 2020 the GMC Sierra 2500 Heavy Duty might have a long list of tricks, but it has just as long a list of new or updated competitors including the 2020 Ram 2500, 2020 Ford 2500 Super Duty, and even its brother, the 2020 Chevrolet Silverado.

With a TCC Rating of 7.0 out of 10 the 2020 GMC Sierra 2500 Heavy Duty has great camera views for towing, a controlled ride, trick engine features, and some innovative solutions to real-life problems, but it gets expensive for a non luxury vehicle, isn’t efficient, and it’s bigger than big.

2020 GMC Sierra 2500 AT4

2020 GMC Sierra 2500 AT4

Hit: Even the hood scoop is packaged with innovation

When equipped with the 6.6-liter turbodiesel V-8 engine option the Sierra HD gets a functional hood scoop. Approximately 40% of the air sucked into the engine goes through the hood scoop along with debris, rain water, and snow. All of these get separated out by centrifugal force and dropped into a round plastic canister. The water needs to go somewhere. GMC engineers created a drain that will automatically open when it detects enough water. The drain can also be manually opened to clear out debris. This is smart engineering.

2020 GMC Sierra 2500 AT4

2020 GMC Sierra 2500 AT4

Miss: It’s massive

My four-door 2020 Sierra 2500 Heavy Duty tester with a standard 6.85-foot bed was 20.83 feet long. It was too long for my house’s standard length garage, not to mention too tall with an overall height of 6.7 feet. The hood scoop was at my shoulders, and I’m 5’10”. Thank heavens the block heater plug is in the lower front bumper. The truck stuck out of a normal parking spot by a large margin and dwarfed a Nissan Murano parked next to it. It feels as wide as a normal highway lane. Parking it in a covered parking garage is an exercise in patience, skill, and confidence. Trucks don’t need to be this big.

2020 GMC Sierra 2500 AT4

2020 GMC Sierra 2500 AT4

Hit: Finally, an integrated block heater

Sierra Heavy Dutys with the expensive $9,890 turbodiesel engine are equipped with a block heater. The days of the little black three-prong plug dangling from the bumper covered in ice and snow might finally be behind us. No more popping open the hood to find where the block heater cord fell to when the zip tie broke. There’s now a covered plug integrated into the lower driver-side bumper with a spring-loaded flip-up cover that keeps dirt, snow, and ice out of the plug. Unfortunately the plug isn’t a standard three-prong and one can’t just use any extension cord. A proprietary plug is used with the supplied 8.28-foot cord.

 

2020 GMC Sierra 2500HD AT4

2020 GMC Sierra 2500HD AT4

Miss: This interior isn’t professional grade

The interior, at best, feels and looks like a minor update to the outgoing 2019 truck’s cabin. Hard plastics are everywhere, the gauge cluster looks dated, the column-mounted gear selector feels cheap, and it’s just a dark place to be. It’s borderline offensive this is the interior GMC offers in a $76,960 vehicle, which is about $4,500 more than a 2020 Chevrolet Silverado High Country LTZ turobdiesel.

2019 GMC Sierra 1500 Denali

2019 GMC Sierra 1500 Denali

Hit: All the information

Towing? Up to 15 camera angles give drivers a view for nearly every type of situation, though some will require accessories to make it all work. An available color head-up display projects vehicle information onto 15 inches of the windshield, including off-road data such as wheel articulation and an inclinometer. It’s the only pickup to currently offer a head-up display and it helps keep the driver’s eyes focused on the road or trail ahead of them.

 

2020 GMC Sierra 2500 AT4

2020 GMC Sierra 2500 AT4

Miss: It’s thirsty

The EPA doesn’t rate heavy duty pickups, but that doesn’t change the fact that the 2020 Sierra HD isn’t efficient. The optional 6.6-liter turbodiesel V-8 with its 445 horsepower and 910 pound-feet of torque averaged just over 14 mpg in cold weather in mixed suburban driving on school runs and on the highway. Even though it was unloaded and never working, it’s right in line with other heavy duty turbodiesel trucks. That’s the best it’s going to do, and once it’s put to work the number will get smaller. The fact that it’s 7,749 pounds as tested certainly didn’t help the situation.

 

2020 GMC Sierra 2500 AT4

2020 GMC Sierra 2500 AT4

Hit: High idle switch

Nobody wants to get into a freezing cold truck on a winter day, and today’s heavy duty pickups have massive engines that can take a while to warm up. A $200 stand-alone feature for the turbodiesel Sierra HD called a High Idle Switch enables the engine to idle at a higher rate of 1,200 rpm to get the fluids flowing quicker. It’s a trick feature to speed up cabin and engine heating that would be handy on every vehicle in the middle of winter in my Minnesota and other cold weather states. But it also lowers efficiency as it’s burning extra fuel to increase the engine’s idle speed.

At $79,960 as tested the 2020 GMC Sierra 2500 Heavy Duty was downright expensive. It was well equipped with an 8.0-inch touchscreen infotainment system with Apple CarPlay and Android Auto, head-up display, LED lighting, heated leather seats (cooled in the front), AT4 off-road package, turbodiesel engine, gooseneck tow package, and driver alert package with forward collision warning, automatic emergency braking, and lane departure warning.

The heavy duty pickup truck segment is full of winners at this point. Each of the trucks will get the job done, but how each truck goes about getting that job done varies greatly. The 2020 GMC Sierra 2500 HD packs cool technology, but its interior falls a bit short, especially at this high price.

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2020 GMC Sierra 2500 4WD Crew Cab AT4
Base Price: $41,595
Price as tested: $76,960
EPA fuel economy: N/A
The hits: Thoughtful tech, lots of power, smart packaging
The misses: Massive, thirsty, expensive, depressing interior

2020
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2020
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