2020 GMC Sierra AT4 – A Sierra for everybody

Canadians love their GMC pickups. They prefer the Sierra over its Chevrolet Silverado sibling. The product planners have ensured there is a GMC Sierra for everybody.


There are dozens of configurations involving cabs (regular, crew or double), boxes (standard, short or long), and six trim levels. You can choose from six different engines, three transmissions and two or four-wheel-drive.

That’s before you even get to the extensive option book!


Pickup trucks today rival luxury vehicles – in amenities and price

Pickups have evolved to the point where they can be equipped to rival luxury vehicles, with price tags approaching $100,000 when fully optioned. The latest trend in full-size pickups adds more rugged looks and off-road capability, combined with many of those luxury-oriented features and creature comforts.

Case in point – the 2020 GMC Sierra AT4.

The $63,000 starting price for the AT4 is almost exactly double that of the base Sierra pickup. But that kick-off point brings an extremely well-equipped truck.  Leather seats, power everything, a premium audio system, navigation, heated front and rear seats, dual zone automatic climate control etc.

If you stopped there, you’d have a pretty impressive truck!

2020 GMC Sierra AT4


The bottom line for the test vehicle, included $12,640 in options. I won’t bother reporting on comfort, convenience, ride, handling and performance – all of which are class competitive. I did not seek out a way to test the ability to carry 700 kg or tow 4,44 kg.

Instead I’d like to concentrate on three unique features: AT4 trim, the ‘light-duty’ diesel engine and a carbon composite box with a slick multi-function tailgate.


The AT4

This new trim level slots in above the SLT and below Denali.

It brings all the good stuff from the $60,000 SLT, including the Multi-Pro tailgate and LED headlights. To this, it adds a five-centimetre factory-installed lift kit, heavy duty two-speed transfer case, unique integrated dual exhaust system, trailering package with visual hitch guidance.

There’s also an automatic locking differential, traction select system with off-road mode, off-road suspension with Rancho monotube shocks and skid plates.

The AT4 trim also brings a unique grill, lots of gloss black trim and a leather interior.

Needless to say, the AT4 brings some serious off-road cred.


Duramax Diesel – Quiet and smooth, it impressed from the outset

The Sierra can be equipped with four, V6, and eight-cylinder gasoline engines ranging in horsepower from 285 – 420 and,  the more important figure – 305-460 lb. ft. of torque.

The heavy-duty Sierra can be had with a 6.6-litre V8 Duramax diesel, that produces a whopping 910 lb. ft. of torque.

Duramax is a joint venture of GM and Isuzu. More than 2.5 million high pressure, common rail, direct-injected V8 diesel engines have gone from that plant to GM assembly lines since 2001. Production began last year on a new in-line, turbocharged, 3.0-litre six-cylinder ‘light duty’ Duramax diesel.

This engine was developed specifically for full-size GM pickups and body-on-frame SUVs.


This new small Duramax diesel produces the same amount of torque as the largest-available V8 gas engine, but at much lower rpm. It also yields fuel economy numbers that are uncommon in a full-size pickup.

Paired exclusively with GM’s new 10-speed automatic transmission, it carries a tow rating of 9,100 pounds and a payload of 1,830 pounds.

Boasting a raft of innovative and high-tech features, it is rated at 10.5 litres/100 in the city and 9.1 on the highway. Quiet and smooth, it impressed from the outset.

During a week of mixed city/highway driving, I witnessed an average of 9.8 litres/100 km. That was better than the mid-size crossover tested under the same conditions the following week! My experience with full-size pickups under similar conditions is 14-16 litres/100 km.


Carbon Composite Box – Tougher than steel

It may seem strange to talk about weight reduction in a 6,000-pound vehicle. But every little bit helps, when that saving allows a bigger payload.

The CarbonPro composite box is not only lighter, but tougher than steel.


Multi-Pro Tailgate – Swiss Army knife of tailgates

The Multi-Pro tailgate is like a Swiss Army knife, bristling with features and configurations. There are three parts and at least six functions. The MultiPro consists of a primary conventional tailgate. Incorporated within is a second smaller tailgate. Integrated in that is a fold-out stop/step mechanism.

Let’s walk through some of the configurations.


Primary Tailgate

Press one of two rubber-coated buttons and the main tailgate lowers automatically. You can also lower it with a button in the cab.


Load stop

With the tailgate in the lowered position, you can press a large button and flip up a panel that prevents cargo from sliding off the bed/tailgate.



Or you can press another button and the integrated secondary tailgate drops open all the way and provides a nice, easy step for access to the box. The step is rated for 375 pounds so even a large person carrying a heavy item is safe. There is also a fold-away handle on the left side of the box you can grab to help get aboard.


Work surface

With the primary tailgate in the raised position you can lower the secondary tailgate resulting in a chest-level work surface 25-cm in depth.

The 2020 GMC Sierra AT4 with the composite box and multi-purpose tailgate provides enough unique features to stand out in a crowded field.


FACTS & FIGURES – 2020 GMC Sierra 1500 4WD crew cab 147” AT4


Base: $63,098 (AT4 trim)

As tested: $77,738 including freight



Pedestrian braking, forward collision alert, following distance indicator, lane keep assist with lane departure warning, blind spot monitor, rear cross traffic alert, IntelliBeam headlight control with automatic high beams



20-cm colour multi-touch display, Bluetooth streaming audio, Android Auto and Apple CarPlay capability, voice recognition, in-vehicle apps, personalized infotainment and vehicle setting profiles, Hitch Guidance with hitch view, satellite radio, 4G LTE Wi-Fi Hotspot capability



Power sliding rear window, power windows, locks and front seats, perforated leather-appointed front seats, premium infotainment system with navigation, wireless charging, seven-speaker Bose audio system, heated front and rear seats, ventilated front seats, heated tilt & telescope steering wheel, two 120-volt outlets, dual zone automatic climate control



Power sunroof, $1,325; Technology package, (Surround Vision, Rear Camera Mirror, Bed View Camera, 38-cm Heads-Up Display, black mirror caps) $2,520; 3.0-litre Duramax diesel engine, $3,245; AT4 Carbon Pro edition (Unique Grille Surround, Carbon Composite Bed, Black dual exhaust tips, 20″ six-spoke Carbon Grey painted aluminum wheels), $4,790; Driver Alert package (Automatic Emergency Braking, Front Pedestrian Braking, IntelliBeam headlamps, Adaptive Cruise Control, Camera, Following Distance Indicator, Front and Rear Park Assist, Lane Change Alert with Side Blind Zone Alert, Rear Cross Traffic Alert), $1,260



Ford F-150, Ram 1500, Toyota Tundra



Engine: turbocharged six-cylinder diesel, 277 horsepower, 460 lb.-ft. of torque, diesel fuel

Transmission: 10-speed automatic, four-wheel-drive

NRCan rating (litres/100km city/highway): 10.5 / 9.1

Length: 5,886 mm

Width: 2,063 mm

Wheelbase: 3,747 mm

Weight: 2,520 kg


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