GMC Sierra AT4 — Off-road performance

By Jim Meachen and Ted Biederman

In years past there hasn't been much to distinguish the GMC Sierra from the Chevrolet Silverado other than the Sierra was more feature-laden and came in at a higher price point. It seems one of General Motors' goals with its all-new-for-2019 full-sized trucks was to better differentiate appearance and personality that easily distinguishes the brands giving the GMC a clear-cut personality of its own.

This may be a good thing for GMC because of all the negative vibes generated over the Silverado styling, particularly the double-stacked, squinty-eyed front-end treatment. The GMC now has a bolder in-your-face big-truck look with a huge grille and a large-yet-modern headlight design.

For example the Sierra AT4 for 2019 shows unique sheetmetal including the bolder front-end, and exclusive content to separate it from its sibling — including a cargo box made of carbon fiber, a versatile split-folding tailgate, and optional retractable steps that can pivot rearward to aid bed access.

GMC calls the pickup tailgate the most innovative ever, with six unique functions and positions offering enhanced second-tier loading, a standing workstation, and easy access to items in the box. GMC says the carbon fiber pickup box is an industry first, developed to increase durability, efficiency and functionality while offering best-in-class dent, scratch and corrosion resistance.

Even as the Sierra seems to have more individuality this time around the GMC and Chevrolet trucks are more alike than different. Both share the same five powertrains, frames, cabs and most of the interior. While not in the same class as Ram's new upscale interior, we like GMC's layout and we have no qualms over the overall design and material quality.

The Sierra comes in six trim levels — Base, SLE, Elevation, SLT, AT4 and Denali. While the base is a work-only truck, the SLE brings such things as a 17-inch alloy wheels, a damped tailgate, leather-wrapped steering wheel and an 8-inch touchscreen. More standard equipment and packages are available through the trim levels. The AT4 stands out for its considerable off-road capability.

The Sierra comes in regular cab, double cab and crew cab. Regular cab models get an eight-foot box, the double cab comes with a 6-foot-6 box, and crew cabs are available with a 5-foot-8 box or a 6-foot-6 box. Five engines — including a turbocharged 4-cylinder — and three transmissions are available.

The choices are a base V-6 making 285 horsepower and 305 foot-pounds of torque paired to a six-speed automatic. For the first time a turbocharged 2.7-liter four-cylinder engine is available making 310 horsepower and 348 foot-pounds of torque. The most popular choice is the 5.3-liter V-8 producing 355 horsepower and 383 foot-pounds of torque. It can be paired with either a six- or eight speed automatic. The most fuel-efficient engine is the all-new 3.0-lier inline 6 Duramax turbo-diesel making 277 horsepower and 460 pound-feet of torque. It has just been released so check for availability.

The king of the hill is the 6.2-liter V-8 making 420 horsepower and 460 pound-feet of torque mated to a 10-speed automatic. That was the combination on our AT4 test truck and it proved dramatically proficient especially with light loads. Towing capacity is 12,200 pounds and payload is rated at 2,240 pounds. Note that the big engine and 10-speed are available only in the pricier AT4 and Denali trims.

In addition to its ability to move confidently when required, the AT4's handling belied the fact it is a big truck. It exhibited responsive steering and restrained body roll. How fast is fast in a big pickup? It has been measured at 5.8 seconds from 0-to-60 with the ability to reach a quarter mile in 14 seconds at 100 mph. To get the fastest starts put the truck in 4-Hi and use the Sport mode. The AT4 also stops fast (for a big truck) coming down from 60 mph in 128 feet. The big downside as you might expect is in gas mileage. The 6.2-liter V-8 is rated at only 15 mpg in city driving, 19 on the highway and 17 combined. Premium gas is required.

Prices start at $31,195 for bare bones single cab work truck with the base V-6 engine, and range through the trim levels to the loaded luxury-infused Denali crew cab starting at $59,895 including the $1,595 destination charge. A myriad of options can bring the price up near six figures including the $2,495 charge for the 6.2-liter engine.

Our AT4 test truck with the big engine and several other options totaling $12,250 carried a bottom line of $66,445 including destination charge.

Base price: $31,195; as driven, $66,445
Engine: 6.2-liter V-8
Horsepower: 420 @ 5,600 rpm
Torque: 383 foot-pounds @ 4,100 rpm
Transmission: 10-speed automatic
Drive: 2-wheel and 4-wheel
Seating: 2/3
Wheelbase: 147.5 inches
Length: 231.7 inches
Curb weight: 5,015 pounds
Turning circle: 46.9 feet
Towing capacity: 12,200 pounds
Payload capacity: 2,240 pounds
Fuel capacity: 24 gallons (premium)
EPA rating: 15 city, 19 highway, 17 combined
Also consider: Chevrolet Silverado, Ram 1500, Ford F-150

The Good
• Several powertrains to suit needs
• Touchscreen easy to use
• Crew cab offers massive rear legroom
• New adaptable tailgate

The Bad
• Interior design looks dated

The Ugly
• Big engine, 10-speed only in top 2 trims