Expert Reviews

First Drive: 2019 GMC Sierra AT4

The Otay Mountain Truck Trail is fun and scenic, but it’s not especially challenging.

Actually, I should qualify that. From a psychological perspective, it’s very challenging. As it spirals around the mountain, the dust-laden track is often just wide enough for tires to fit into the corduroy, water-scarred ruts. At the edge of it, the hill faces fall straight off, and there are no guardrails to speak of. Bounce your right rear wheel too fast off a pit and you might land with your left rear pucker-inducingly close to the edge.

Truthfully, though, no one with any off-roading experience – or a basic modicum of self-preservation – is likely to do that. Going at a reasonable pace, the 2019 GMC Sierra AT4 breezed through the trail so effortlessly that we never even bothered to drop the transmission into low. There was more to be experienced in the sweeping mountaintop views over San Diego and across the border into northern Mexico than in how the truck performed.

The Sierra AT4 is capable of so much more, and Southern California is full of fantastic off-road trails. So, why choose this one? Well, it seems a certain government shutdown may have put a bit of a kink in the original plans.

No matter: the drive was entertaining, and we ended it at a shorter, manufactured off-road course better suited to demonstrating what the AT4 can do: kicking around massive amounts of dirt, and crawling up and down a 21-degree rock grade, an angle verified by the on-board incline meter.

What’s an AT4?

This is GMC’s new off-road badge. Starting with the Sierra – and then, as announced yesterday, the Sierra Heavy Duty – models bearing this name will be working their way into the GMC SUV and truck line-up over the next couple of years. On the SUVs, for the most part they’ll be closer to appearance packages. The trucks, though, will come with more dedicated off-roading bits.

Which Off-roading Bits?

Standard equipment includes all the stuff you’d expect: four-wheel drive with a two-speed transfer case and a locking rear differential, off-road-tuned Rancho monotube shocks, skid plates, a two-inch factory suspension lift kit, 18-inch dark-tint machine-faced wheels with 33-inch all-terrain tires, GMC’s clever six-mode MultiPro tailgate, vertical red recovery hooks, hill-descent control, a traction mode selector, and a bunch of black chrome and body-colour exterior finishing pieces. On the crew cab, heated and ventilated front seats are included, as are heated rear outboard seats.

The standard engine is the 5.3-litre V8 with cylinder deactivation from the Sierra 1500 lineup, which is good for 355 hp and 383 lb-ft of torque at 4,100 rpm and comes paired with an eight-speed automatic transmission.

To get into the available 6.2-litre V8 with cylinder deactivation and its 420 hp, 460 lb-ft of torque at 4,100 rpm, and accompanying 10-speed automatic transmission – which sounds fantastic, by the way – you can either pay $2,895 for the engine upgrade on its own or $6,240 for the off-road performance package, which adds a cat-back performance exhaust system and performance air intake for an extra 15 hp and 9 lb-ft.

A Duramax 3.0-litre inline-six turbo-diesel, matched with the same 10-speed automatic transmission, will be added to the lineup at a yet-to-be-determined later date.

Other available features include a multi-colour head-up display, GM’s rear camera mirror, the GMC-exclusive carbon-fibre-lined box, 33-inch mud terrain tires or 20-inch wheels with all-terrain tires, and other variously packaged safety and convenience features.

Ugh, But It’s Awful On-road, Right?

Well, actually no. Here’s the thing: off-roaders are often bouncy and noisy and just plain annoying in everyday driving, but the Sierra AT4 doesn’t come across that way. On the interstates and side roads around San Diego, a bit of noise transfer from the tires comes through, but for the most part the cabin is quiet enough and the suspension is stable and smooth. The transmission had one or two surprise gear drops, but you get that with a lot of 10-speed automatics. Given what it does for fun, this truck takes care of the business end of things very well.


Sure, it’s no Ford F-150 Raptor – but it’s also not nearly as expensive. The Ram Rebel is a closer comparison, and the Sierra AT4’s available higher power output at a slightly higher price point might be just the thing to push buyers over. This truck does a great job of being a wolf in sheep’s clothing, or a tattooed dude in a suit: it’s a good, reliable daily when you need it to be, but when you’re ready to let your hair down, all you need to do is call.

The 2019 GMC Sierra AT4 gas-powered models are on sale now with diesel availability to come at a later date.

2019 GMC Sierra AT4 Packaging and Pricing

All prices include freight, PDI, and AC tax.

Double cab, standard box (79.44 inches): $61,295

Crew cab, short box (69.92 inches): $63,495

Crew cab, standard box (79.44 inches): $63,795

Upgrade any of these to the 6.2-litre V8 and 10-speed automatic transmission: $2,895

The off-road performance package ($6,240) equips the 6.2-litre V8 engine and adds Goodyear Duratrac tires to go with 18-inch machined aluminum wheels with dark grey accents, the performance air intake system, and a cat-back performance exhaust.

These last two items can be added on their own by equipping the performance upgrade package ($3,020).

The AT4 preferred package ($1,995) adds on a wireless phone charger, rear sliding power window, the 8-inch infotainment screen with on-board navigation, a Bose premium audio system, and a universal home remote. A power sunroof can be added to this package for $1,325 more.

The AT4 premium package ($3,995) includes the features from the preferred package and adds front and rear park assist, lane-change alert with side blind zone alert, rear cross-traffic alert, trailer tire pressure monitoring, and 6-inch black running boards.

With the assist step and tonneau package ($1,725), the running boards can be added separately along with a tri-fold tonneau cover.

The technology package ($2,495) includes HD surround vision, the rear camera mirror, the 15-inch diagonal head-up display, and the 8-inch driver information centre (the colour screen between the gauges).

Driver alert package I ($1,095) includes lane change alert with side blind zone alert, rear cross-traffic alert, front and rear park assist, and perimeter lighting.

Driver alert package II ($855) adds the safety alert seat (the one that buzzes your butt to get your attention), low-speed forward automatic braking, lane keep assist with lane departure warning, front pedestrian braking, forward collision alert, following distance indicator, and automatic high beams.

A console vault and rear under-seat storage can be added with the cargo convenience package ($660), and the trailer camera package ($505) equips left- and right-side mirror cameras and a port for a rear auxiliary camera.

Upgrading to the 20-inch machined aluminum wheels costs $1,395 more, while an upgrade to Brembo six-piston front calipers and 16.1-inch Duralife rotors adds $3,820 to the purchase price.