2024 GMC Sierra HD

Overview

GMC Sierra HD pickups can pull a titanic amount of weight, but their Herculean efforts don’t stop there. These big-power workhorses clean up pretty well, too, offering shiny chrome exterior bits and a comfortable leather saddle for the inside. The Sierra 2500HD and 3500HD are the jumbo-shrimp of their half-ton counterpart, the Sierra 1500, reviewed separately. These GMC pickups offer a higher level of luxury and finish versus Chevy’s Silverado HD offerings. A 401-hp 6.6-liter V-8 with a 10-speed automatic serves as the base powertrain, while an available 445-hp Duramax turbodiesel V-8 with 10-speed automatic transmission is a prerequisite for the Sierra HD’s 22,500 pounds of maximum conventional towing. Additional trailer assist features such as Transparent Trailer View, Trailer Side Blind Zone Alert, and available adaptive cruise control with trailering make the Sierra HD work smarter instead of harder. While the heavy-duty Sierra lacks the polish and max towing of competitors such as the Ram HD and Ford Super Duty, it’s a solid choice for those with a gaping truck-size hole in their heart.

What’s New for 2024?

GMC’s burliest pickup gets a light visual refreshing among larger changes such as a revised powertrain that offers more towing capacity and an all-new trim. The Sierra HDs get a revised front fascia with newly available LED headlights and taillights with sequential turn signals. The 6.6-liter Duramax turbocharged diesel V-8’s power and torque have increased to 470 horsepower and 975 pound-feet of torque respectively. The increased power has increased the towing capacity across the Sierra 2500HD and 3500HD lineup, with a higher max rating of 22,500 pounds at the hitch. The 401-hp 6.6-liter V-8 gas engine’s six-speed automatic is replaced by the Allison-certified 10-speed automatic, previously exclusive for the diesel engine. An all-new Denali Ultimate trim joins 2500HD and 3500HD and offers an even greater level of luxury than the popular Denali tier. Denali Ultimate, just as it does for Sierra 1500, adds leather-wrapped door panels, steering wheel, and A- and B-pillar handles. The 16-way power-adjustable front heated and cooled messaging front seats are also given intricate leather stitching with a topographic map of Mount Denali in Alaska. These revisions are supplemented by new trailering technology, including adaptive cruise control with trailering, gross combination weight (GCW) alert, and GM’s Transparent Trailer View is now also compatible for gooseneck and fifth wheel trailering. The Sierra HD’s standard driver assistance tech has also been expanded for 2024.

Pricing and Which One to Buy

Pro

$45,000 (est)

SLE

$50,000 (est)

SLT

$60,000 (est)

AT4

$68,000 (est)

AT4X

$72,000 (est)

Denali

$74,000 (est)

Denali Ultimate

$80,000 (est)

We’d start with the crew cab and choose the standard bed on the Sierra 2500HD. We’d steer clear of the rugged AT4 and chrome-laden Denali models despite their enhanced appearance. Instead, we’d recommend picking the SLT trim level and adding four-wheel drive and the diesel V-8. The SLT comes standard with GMC’s versatile MultiPro tailgate, a heated steering wheel, heated front seats, power-adjustable front seats, and remote start. It also unlocks more options than the lesser SLE trim. We’d pick the SLT Convenience package that includes front bucket seats with ventilated cushions, heated rear seats, and a power-sliding rear window. The Driver Alert packages are also worth adding because they make the behemoth easier to live with thanks to assists such as blind-spot monitoring, lane-departure warning, and front and rear parking sensors.

Engine, Transmission, and Performance

The Sierra HD comes standard with a gas-powered 6.6-liter V-8 that generates 401 horsepower and 464 pound-feet of torque. It pairs with a 10-speed automatic transmission and rear- or four-wheel drive. The optional Duramax diesel 6.6-liter V-8 cranks out 470 ponies and 975 pound-feet of twist, and it works through an Allison-certified 10-speed automatic. You can also specify either a single- or dual-rear-wheel axle (known as a “dually”) for 3500 HD models. While we’ve only driven an earlier diesel version, we did sample the gas-burning powertrain on the internally identical Chevy Silverado 2500HD and appreciated its dutiful behavior. However, there’s no arguing that the Duramax is a highlight of the heavy-duty Sierra, and it’s a no-brainer for those who regularly tow substantial loads. The engine is surprisingly refined, and the transmission is very responsive. Together they helped the 2500HD Denali we tested achieve impressively quick acceleration times. The gigantic GMC also has an agreeable ride quality for its breed. Though its steering is vague at highway speeds the Sierra nonetheless feels more agile than its heavy-duty competitors. The trail-ready AT4 and AT4X models are a more-rugged take on the commonly chrome-riddled rig, with an off-road suspension and a locking rear differential to go with its otherwise blacked-out aesthetic.

More on the Sierra HD Pickup Truck

Towing and Payload Capacity

The strongest Sierra 3500HD can pull as much as 36,000 pounds. However, those massive capacities require the diesel engine, regular cab, rear-wheel drive, the dual-rear-wheel axle, and a gooseneck hitch. The same truck with a fifth-wheel hitch drops the capacity to 32,000 pounds. The Sierra 2500HD is only offered with a single-rear-wheel axle, and its burliest version is good for 22,500 pounds of towing.

Fuel Economy and Real-World MPG

Since the EPA doesn’t test vehicles as heavy as the Sierra HD and its gigantic competitors, we can only judge their real-world mpg on our highway fuel-economy route. We’ve only tested a Sierra 2500HD Denali with the diesel engine, which earned 17 mpg on the highway. For comparison, the diesel-powered Silverado 2500 LTZ crew cab and Ram 2500 Tradesmen regular cab diesels we tested both managed 19 mpg. Those who stick with the GMC’s standard gas-fed V-8 should expect to see even worse fuel economy than the diesel option.

Interior, Comfort, and Cargo

Inside, the Sierra 2500HD and 3500HD have a huge dashboard that hosts user-friendly switchgear. Most models have a split-folding front bench that can be replaced with a pair of bucket seats and a full center console. The Sierra’s interior can also be optioned with a head-up display, a heated steering wheel, heated-and-cooled front seats, and wireless charging. Unfortunately, the cabin’s panel fits and material quality are mediocre at best. While there’s an abundance of soft touch surfaces throughout, and most models benefit from durable plastics, the top-of-the-line Denali falls woefully short of its luxury billing. The new Denali Ultimate trim is as grandeur as it gets, with leather-wrapped interior pieces, Paldao wood trim pieces, and a soft microsuede headliner. The fanciest alternatives from Ram overshadow the GMC largely thanks to their significantly more upscale look and feel. Still, the Sierra HD will please pickup-truck buyers who prioritize practicality and versatility. Along with extensive passenger space in the crew cab, the GMC is littered with handy interior cubby storage. Its standard and long cargo boxes have built-in steps on both sides of the bed and the rear bumper has them at each corner. The box can be further customized with LED lighting, movable tie-downs, and a 120-volt outlet. The heavy-duty Sierra’s biggest showpiece is its innovative multi-function tailgate, which has six different positions that include a work surface and bench. It’s a tailgater’s dream come true.

The Car and Driver Difference

Infotainment and Connectivity

Every Sierra HD has a standard touchscreen infotainment system with Apple CarPlay and Android Auto. While base models have fewer options, they can still be outfitted with a 120-volt outlet and a mobile hotspot. Most trim levels have an 8.0-inch screen and additional charging ports. All systems include a set of rotary knobs and physical buttons that are easily accessible. The larger touchscreen can be upgraded with built-in navigation, a Bose audio system, SiriusXM satellite radio, and a rear-seat entertainment system. A massive 13.4-inch infotainment touchscreen offers the most integrated experience with features like Google Built-in, split-scren navigation, and is wireless Apple CarPlay and Android Auto compatible. This display is standard on Denali and Denali Ultimate trims. GMC also offers a smartphone app that can be used to remotely control trailer functions. Likewise, the truck’s infotainment system allows users to store different trailer profiles to monitor maintenance.

How to Buy and Maintain a Car

Safety and Driver-Assistance Features

While the truck can be equipped with various driver-assistance technology, only a portion of them come standard, and heavy-duty rivals offer even more assists. However, the GMC does have a comprehensive camera system that features up to 15 different viewing modes, including a “transparent” mode that allows the user to virtually see through an attached trailer as if it wasn’t there. For more information about the Sierra HD’s crash-test results, visit the National Highway Traffic Safety Administration (NHTSA) and Insurance Institute for Highway Safety (IIHS) websites. Key safety features include:

Standard forward-collision warning and automated emergency braking Standard lane-departure warning Available blind-spot monitoring and rear cross-traffic alert

Warranty and Maintenance Coverage

GMC provides a competitive warranty plan that matches the coverage provided by its Ford and Ram rivals but, unlike those alternatives, it does include one complimentary scheduled maintenance visit.

Limited warranty covers three years or 36,000 miles Powertrain warranty covers five years or 60,000 miles Complimentary maintenance is covered for the first year

Specifications

Specifications

2020 GMC Sierra 2500 Denali 4WD Crew Cab

VEHICLE TYPE

front-engine, rear-/4-wheel-drive, 5-passenger, 4-door pickup

PRICE AS TESTED

$78,455 (base price: $65,295)

ENGINE TYPE

turbocharged and intercooled pushrod 32-valve diesel V-8, iron block and aluminum heads, direct fuel injection

Displacement

403 cu in, 6599 cc

Power

445 hp @ 2800 rpm

Torque

910 lb-ft @ 1600 rpm

TRANSMISSION

10-speed automatic

CHASSIS

Suspension (F/R): control arms/solid axle

Brakes (F/R): 14.0-in vented disc/14.1-in vented disc

Tires: Goodyear Wrangler Trail Runner A/T, LT275/65R-20 126/123S M+S

DIMENSIONS

Wheelbase: 158.9 in

Length: 250.1 in

Width: 81.9 in

Height: 79.8 in

Passenger volume: 139 cu ft

Curb weight: 8260 lb

C/D
TEST RESULTS

Rollout, 1 ft: 0.3 sec

60 mph: 6.5 sec

90 mph: 14.4 sec

Rolling start, 5–60 mph: 7.7 sec

Top gear, 30–50 mph: 3.7 sec

Top gear, 50–70 mph: 5.0 sec

¼-mile: 15.0 sec @ 92 mph

Top speed (governor limited): 98 mph

Braking, 70–0 mph: 207 ft

Roadholding, 300-ft-dia skidpad: 0.73 g

C/D
FUEL ECONOMY

Observed: 12 mpg

75-mph highway driving: 17 mpg

Highway range: 610 miles

EPA FUEL ECONOMY

Combined/city/highway: not rated

More Features and Specs