Expert Reviews

2020 GMC Sierra 1500 First Drive Review

AutoTrader SCORE
This score is awarded by our team of expert reviewers after extensive testing of the car
  • Safety

ALPINE, Wyoming – A towering mountain of rocks, tall as a two-storey house – and beyond it, an enormous pit roofed with logs, like a giant, Amazonian tiger trap. Though I wondered aloud what its purpose was, eyeing the trap with a twinge of apprehension, on some level I just knew we’d eventually end up driving over the thing.

Saddling up an AT4, an off-road-focussed trim level that GMC introduced on the Sierra for 2019, we pointed its nose at the near-vertical wall of rocks and pressed “go”.

It was a fine way to show off the versatility of GMC’s new Sierra 1500 AT4 with 3.0L Duramax, a new diesel engine that just debuted in the Silverado. Off-roaders don’t need the speed nor the voracious fuel appetite of an enormous V8, relying more on a steady supply of available torque. The new inline-six diesel has 277 hp, but more importantly, 460 lb-ft of torque that arrives at just 1,500 rpm. Setting the drive mode to 4-Lo, we clamber slowly up the jagged rocks, rocking fore and aft, and from side-to-side, stones pinging off the underbelly skid plates. Cresting the hill, we perch precariously at the top until I select Hill Control, and the truck calmly maintains a slow, 6 mph descent down into the tiger pit, and out through the other side.

Styling: 7/10

The AT4 off-road brand was introduced on the Sierra for 2019, and has since started appearing throughout GMC’s truck and SUV lineup. On the Sierra 1500, this trim level eschews the chrome embellishments for a more aggressive blacked out grille, two-inch lift, signature 18-inch wheels wrapped in knobby, Duratrac rubber, and eye-catching red tow hooks. It’s a good-looking, purposeful off-roader. The cabin, however, is bland and uses plenty of hard plastics. Contrasting seat inserts and stitching do add some visual flair; however, the small touchscreen and nondescript gauges look outdated when compared to its competitors.

Safety: 8/10

New for 2020, the Sierra 1500 now includes adaptive cruise control, which can bring the truck to a complete stop. Other safety updates include the rear camera mirror, which uses a rear high-resolution camera to project onto the rear mirror a clear view, uninterrupted by passengers, cargo, or headrests; and a 15-inch multi-colour head up display.

Also new is the brilliant Pro-Grade trailering app, with a suite of cameras providing up to 15 different views. With this app, the driver selects a button on the touchscreen for a bird’s-eye view of the trailer hitch, complete with guideline, for easy, one-person hitching. Using either turn signal gives you a side view of the trailer, letting you know that the coast is clear for turning and there are no vehicles, obstacles, or ditches in the way. Perhaps the slickest part of this technology is the “invisible trailer” which combines views from all the cameras to simulate a glass trailer, clearly showing following or passing vehicles.

Available safety options include blind-spot monitoring and parking sensors. Adding the Driver Alert Package gets you forward collision warning, automatic emergency braking, automatic high-beams, and lane-keeping assist.

Practicality: 7/10

Though many people use their pickup trucks as daily drivers, for urban dwellers it seems almost ludicrous to talk about their practicality. Yet there are large parts of this country where having the ability to tow and haul are an absolute necessity.

The Sierra 1500 isn’t as big or cumbersome as a heavy-duty truck and, equipped with the 3.0L Duramax, can tow up to 9,700 lb with the 2WD 1500 or 9,100 lb with the AT4. There’s plenty of storage space in the generously sized centre console, and numerous door pockets for drinks. Like most of GMC’s products, the Sierra 1500 is also equipped with a Wi-Fi hotspot, an attractive feature for those who use their truck as a work vehicle.

User Friendliness: 7/10

Traditionally, trucks have been seen as little more than blunt tools, simple sledgehammers for getting the job done. But even they are becoming more technologically sophisticated, with systems to help you hitch up easier, tow more safely, and even control your house trailer’s temperature using your smartphone. The Sierra AT4’s knobs and switches are large and clearly marked, with a “4HI/4LO” knob to control the transfer case while off-roading, and, in trucks equipped with the Pro-Grade trailering app, easy-to-use touchscreen buttons to access the camera views. In diesel models, the switchgear includes an exhaust brake with the tow/haul mode. Most of the truck’s functions are ergonomically intuitive and it’s fairly easy to drive.

Features: 7/10

Our AT4 tester is a well-equipped truck that slots in under the top-spec Denali trim. In addition to the blacked-out appearance package, the AT4 comes with a 2-inch lift and Rancho shocks, skid plates, locking rear differential, hill descent control, two-speed transfer case with low-range 4x4 gearing, available Pro-Grade trailering system, 12 cargo tie-downs and available carbon-fibre bed, standard six-position Multi-Pro Tailgate, corner step footwells in the rear bumper, knobby Duratrac tires, heated and ventilated seats, heated steering wheel, head-up display, Wi-Fi hotspot, Bose sound system, high definition digital rear mirror, adaptive cruise control, and available driver safety assist package.

Comfort: 7/10

While the cabin isn’t luxurious, the seats are comfortable and we really appreciated their ventilation in the blazing-hot mountain sun. There’s a heated steering wheel for those cold mornings and the cabin is well-insulated from wind, though the tires do tend to drone on paved roads. Like most trucks, the Sierra 1500 feels more stable and comfortable with the bed loaded, but even unladen it rides well, though the two-inch lift does give it a bit more bounce over bumps.

Driving Feel: 7/10

Both on-road and off, the Sierra AT4 feels solid and composed, with the expected amount of roll from a focussed off-roader. It’s not a hardcore trail machine like the Ford Raptor, nor does it boast the creamy-smooth ride of the Ram 1500’s air suspension. New for 2020 is a 10-speed automatic transmission, and it makes the most of the 277 hp diesel’s powerband, never lagging nor shifting hard. Clambering over really rough ground does produce some lateral toss, but the suspension absorbs most of the motion. Steering is nicely weighted for a big vehicle and overall it’s easy and pleasant to drive.

Power: 7/10

Engine options include a 5.3L V8, producing 355 hp/383 lb-ft of torque, and a 6.2L V8 with 420/460; though our test drives were all conducted with the 3.0L Duramax Diesel-equipped Sierra 1500 AT4, with 277/460. Mated to the new 10-speed automatic transmission, this powertrain is ideal for the off-roader, who needs a low-down supply of steady power rather than speed. Still, the readily available torque lets the Sierra AT4 accelerate quickly enough to merge safely.

Two-wheel-drive models with the 3.0L diesel boast a max tow rating of 9,700 lb and AT4 models up to 9,100 lb. Over a short loop of a few miles around the Snake River mountain range, we towed a 9,000 lb box trailer with a 3.0L AT4. Hauling that size load, the AT4 does take longer to get up to speed, but it’s still a confidence-inspiring rig, especially when equipped with the slick trailering aid tech.

It’s certainly capable, more so than the Ford Raptor with its 8,000 lb tow limit, but less than the new Ram EcoDiesel’s 12,560 lb.

Fuel Economy: 8/10

Though official fuel economy ratings for the Sierra 1500 AT4 with 3.0L diesel aren’t yet available, the similarly equipped Silverado 1500 Duramax is rated at 23 mpg (10.2 L/100 km) city, and 29 mpg (8.1 L) highway. By comparison, Ford F-150 Powerstroke 4x4 is rated at 21 (11.2 L) mpg city and 28 mpg (8.4 L) highway.

Value: 6/10

There are no official Canadian prices released yet for the 2020 Sierra AT4 3.0L Duramax. Last year’s prices for the gasoline-powered AT4 started at $59,800 and you can expect to pay at least $3,000 for the Duramax diesel and 10-speed transmission. Adding all the must-have features like the Pro-Grade trailering app or driver’s safety suite and it’ll start to add up.


The Sierra 1500 AT4 Duramax Diesel could be just the right package for the off-roader who also needs serious towing capacity. It strikes a nice balance between the hardcore Raptor, and the more luxurious Ram 1500 EcoDiesel. More dedicated off-roaders might prefer the less powerful but smaller and more agile diesel-powered Chevrolet Colorado ZR2 – which only has a 5,000 lb tow rating – or wait until the GMC Canyon AT4 trim arrives.

Engine Displacement 3.0L
Engine Cylinders I6
Peak Horsepower 277 hp
Peak Torque 460 lb-ft
Fuel Economy n/a
Cargo Space 5'9.5" / 6'8" bed
Model Tested 2020 GMC Sierra 1500 AT4 Duramax Diesel
Base Price $60,098
A/C Tax $100
Destination Fee $1,900
Price as Tested N/A
Optional Equipment