TruckLove: 2025 GMC Sierra AT4X demands attention

You know that feeling? The one where you’re seated high above the mundane rush-hour traffic, feeling like a benevolent giant surveying the landscape, ready to conquer the next off-ramp or mountain pass? That was me, recently, behind the wheel of the 2025 GMC Sierra AT4X.

Let me be clear: this is not a sales pitch. This is a technical love letter to a machine that manages to bridge the colossal gap between a brutally capable off-road weapon and a genuine, uncompromised luxury vehicle. It’s a truck that can haul a few tons of lumber one day, crawl over a boulder field the next, and then treat you to a back massage on the drive home while you’re enjoying a foot-long sub in the cavernous back cab. It is, quite simply, driving on top of the world.

The AT4X is not just a trim package; it is an engineering philosophy in physical form. Its existence is a challenge to the idea that a serious off-roader must sacrifice on-road refinement. Let’s dive into the guts of this beast, starting with the pièce de résistance: the suspension.

From Conflict to Convert: Why the 2025 GMC Sierra AT4X Made Me a True Truck Fan

I'm having a blast - as you can see in the photo above. Truck life is a lifestyle. As the years of testing the best cars, trucks and SUV's on the market, I have shared how the industry is bringing with them a tidal wave of astonishingly capable and complex pickup designs, I've been pulled into a vortex of respect and admiration. Today, after spending time with the 2025 GMC Sierra AT4X, I can finally say it: I'm a truck fan. And frankly, I’m obsessed.

The AT4X is unlike anything I’ve tested this year. While the competition is fierce—and we’ll get to the performance rivals in a moment—this vehicle strikes an arresting pose from the first glance. It’s an ambitious fusion of bold, strong grille design cues, dynamic color combinations, and high ground clearance that establishes a muscular, almost unapologetic presence. It screams capability. But the drive is what sealed the deal for me.

The Physics of Confidence: Tires and Torque

The first moment you step way up into the cab—a literal climb that immediately announces you're sitting higher than almost everyone else—a flood of confidence hits you. But the real technical heroes making that altitude possible are the tires.

The AT4X rides on aggressive, oversized 35-inch Goodyear Wrangler Territory MT tires. These are not just aesthetic flourishes; they are foundational to the truck’s capability. The massive sidewalls and chunky tread blocks dramatically improve ground clearance and provide necessary grip for serious off-road terrain. This isn't theoretical; this is real-world physics that allows the AT4X to articulate over obstacles the competition can only stare at.

And that capability is instantly accessible thanks to the powertrain. I didn't need a dyno reading to appreciate the sheer grunt of this machine. Forget the number on the horsepower readout for a second; what truly surprised and delighted me was the torque. Whether you choose the throaty 6.2L V8 or the available Duramax diesel, the minute your foot touches that gas pedal, the truck is ready to haul butt. While torque is traditionally measured for towing capacity, the immediate, low-end surge you feel when pulling away from a stoplight is invigorating. It’s a powerful, ready-to-move feeling that makes the AT4X feel surprisingly agile despite its size. I would have loved to take it up into the mountains or out into the desert, or even towing on the bay... Oh, yeah, I don’t have a yacht. Scratch that.

The Power-Luxury Command Center

The cabin of the AT4X is where the truck transitions from an off-road beast to a luxurious, high-tech sanctuary—your own personal command center driving on top of the world.

The seats are less like truck seats and more like captain’s chairs: plush, refined, and totally supportive (even if they lack a little lateral support for high-speed corners). The massive dash is dominated by high-tech elegance: a massive digital driver readout, the black glass of the high-tech infotainment system, and expertly mixed chrome accents.

But let's talk about cab power. This truck is ready for the digital age, whether you’re sealing an art deal (as I often am) or running a mobile office. It features a plethora of places to charge your phone and devices, ensuring you’re never without power. More importantly, the 12-speaker Bose Premium sound system doesn't just deliver audio; it delivers an experience. With speakers strategically placed, including in the doors, the sound clarity is outstanding for everything from music to hands-free calls.

The Back Cab Revelation

If the front is a command center, the rear is a disguised luxury lounge. The back cab is the true secret weapon of the AT4X experience. Hey, I'm a Florida boy, a sun child, a beach lover so I am realizing that trucks could very well fit my ;lifestyle and possibly yours. Just thinking out loud. Look at the back and the cab.

There is ample space—enough room to truly stretch your elbows out, store beverages securely, and enjoy refined climate control with dedicated heating and cooling controls. I confess, I didn’t do a lot of hauling of equipment or art crates during my personal time with it. Instead, I chilled in that back seat quite a bit, enjoying the supreme comfort and incredible sound quality of the Bose system.

The back seat isn't an afterthought; it’s an extension of the luxury experience. I remember thinking to myself, the space back there is so massive, so clean, and so comfortable, I truly could have a small gathering, or even host a tiny, upscale picnic back there (if I folded the seats up). I even asked my lovely driver for the day to take me to one of my appointments as I chilled in the back seat like a boss. You GOT to try that.

The 2025 GMC Sierra AT4X isn't just a tough truck; it's a technical statement about what modern versatility should be. It’s a vehicle that provides the confidence of a rock crawler with the amenities of a luxury sedan, and that dual personality is why I’ve finally become a truck fan.

The Masterpiece of Dampening: Multimatic DSSV

Forget standard twin-tube or even high-end monotube shocks. The AT4X’s secret sauce lies in its Multimatic DSSV (Dynamic Suspension Spool Valve) dampers. This technology, often found in high-performance racing—from Formula 1 to the highest levels of off-road rally racing—is a game-changer for a full-size pickup.

Unlike conventional dampers that use flexible shims or valves to control fluid flow, the DSSV system uses precision-machined, three-stage spool valves. These valves allow for predictable, precise, and repeatable dampening curves that can be tuned independently for different driving scenarios:

1. Primary Valve: Controls the main compression and rebound for normal, everyday driving. This is where the AT4X achieves its surprisingly comfortable, smooth on-road ride, isolating you from minor road imperfections.

2. Jounce (Compression) Valve: Engages during heavy, rapid compression (like hitting a massive pothole or landing a jump off-road). This valve prevents harsh bottom-out events, providing exceptional impact absorption that allows you to attack rough terrain with minimal jarring.

3. Rebound Valve: Controls the return of the shock. This is crucial for high-speed off-roading, preventing the wheels from losing contact with the ground or bouncing uncontrollably.

The result of this sophisticated hydraulic choreography is a ride that reviewers describe as "capable of handling rough off-road terrain with minimal jostling." On the pavement, it eliminates the traditional "bounciness" you often associate with a truck built on a large suspension lift. Coupled with a factory-installed 2-inch suspension lift and available 35-inch tires (which offer a significant increase in contact patch and ground clearance), the DSSV dampers transform the AT4X into a genuine, factory-built rock crawler and desert runner.

Torque, Traction, and Trail Command

The heart of the AT4X’s capability is its powertrain and traction system. While the available 6.2L V8 engine delivers a visceral, classic truck rumble and 420 horsepower with 460 lb-ft of torque, the sheer performance isn't just about output—it’s how it's managed. Paired with a slick 10-speed automatic transmission, the power delivery is always immediate and well-metered, even on tricky climbs.

However, for those who truly speak the language of torque, the Duramax 3.0L inline-six turbodiesel option offers a compelling counter-argument. With its monstrous 495 lb-ft of torque, available low in the rev range, the diesel option provides the kind of low-end grunt you need for controlled rock crawling or pulling a heavy load up a grade.

The AT4X further distinguishes itself with front and rear electronic-locking differentials. This isn't just a limited-slip system; this is a true electronic locker that, when engaged, forces both wheels on an axle to spin at the exact same speed. This level of mechanical grip is mandatory for serious off-roading, ensuring that if one wheel is airborne or on a slick surface, the other is still delivering 100% of the available torque. This dual-locker setup is a significant technical advantage over many competitors and is the difference between getting stuck and effortlessly driving through.

Towing & Hauling Capabilities

Speaking of heavy loads, perhaps you need to pull that Yacht to the bay of beach- you're good to go. In fact, I may have rto consider getting me a yacht just for having a reason to get a truck. Psyche! The AT4X is capable of towing up to 9,000 lbs with the 1500 model, making it perfectly capable for a large boat or a substantial camper. If you need true heavy-duty work, the 2500HD AT4X variant is available, boosting max conventional towing capacity up to 18,500 lbs and max diesel torque to a staggering 975 lb-ft from a 6.6L Duramax V8. The HD version maintains much of the same off-road philosophy but scales the engineering for monumental tasks.

The Yacht-Hauling Fantasy (And Reality)

Now, I mentioned the whole "not owning a yacht" thing earlier, but let’s look at those numbers again. Nine thousand pounds of towing capability in the 1500 model? That is enough for a serious boat or a camper that probably has better Wi-Fi than my house. But then you look at the 2500HD AT4X with its 18,500 lbs max capacity and the staggering 975 lb-ft of torque from the Duramax V8, and suddenly, you feel qualified to manage a major logistical operation. I found myself driving around South Florida, mentally scanning every object, asking, Could I tow that? A semi-trailer? Probably. A small apartment complex? Maybe on a good day. My neighbor’s questionable choice of garden gnome collection? Absolutely, with enough ease to leave a perfect burnout circle in his driveway (purely for torque testing purposes, of course).

The confidence this torque provides is almost reckless. You realize the truck is so capable, you could accidentally forget you’re towing anything at all. The last thing you want is to be cruising down the highway, feeling that smooth, plush massage on your back, listening to the Bose system, and suddenly looking in the mirror to realize you’ve been doing 80 mph with a three-story mobile home behind you. It’s the kind of power that requires a responsible adult at the wheel—which is why I'm conflicted. I spent more time marveling at the truck's ability to barely notice the large, heavily fortified art crate I was "towing" (read: hauling one block down the street) than I did actually focused on the road. The AT4X has enough raw, luxurious muscle to make you feel like you should be piloting a battleship, even when you're just picking up take-out.

An Upscale Command Center: The Tech & Comfort Thesis

The second pillar of the AT4X philosophy is luxury. Stepping up into the cab is a literal climb—a necessary consequence of the lift and ground clearance—but once you're inside, you are no longer in a rugged work truck; you are in a premium, leather-lined, technology-driven command center.

This is where the AT4X shines—it understands that conquering an 8-hour trail ride is just as fatiguing as a cross-country haul, and it provides the necessary amenities to keep the driver fresh.

On the technology front, the digital real estate is immense and seamless:

• 13.4-inch Infotainment Screen: A massive, responsive display with native Google built-in capability, ensuring effortless navigation and media access.

• 12.3-inch Digital Instrument Cluster: Fully customizable, putting critical vehicle data like pitch, roll, and differential status directly in your line of sight.

• 15-inch Head-Up Display (HUD): Projects essential information—speed, navigation, and off-road gauges—onto the windshield. This allows the driver to keep their eyes on the trail, which is a critical safety and performance feature when tackling technical terrain.

My personal experience driving the AT4X was nothing short of brilliant. Whether I was kicking up dust on a back trail or just chilling in the spacious, quiet back seat enjoying a quick lunch (seriously, there’s enough room back there for a small picnic table), the cabin remained a sanctuary. Hauling a heavy load of landscaping supplies felt less like work and more like an effortless demonstration of brute force, thanks to the sheer torque and the confidence of the ProGrade Trailering System cameras.

The Obsidian Rush interior trim, complete with genuine Vanta ash wood, is a masterclass in modern luxury vehicle design. The front seats are not just heated and ventilated, they feature a massage function and are 16-way power-adjustable.

The Price of Admission and the Competition

This kind of dual-purpose engineering and luxury doesn't come cheap, nor should it. The 2025 GMC Sierra AT4X, specifically the 1500 Crew Cab model, starts at a price point around $81,595 MSRP (before options). The 2500HD AT4X naturally climbs higher, starting in the $83,200 range. The higher cost-to-own figures reflect the premium parts, complexity, and sheer scale of the vehicle.

So, who is the AT4X competing against?

The AT4X's unique selling proposition is its unyielding commitment to both worlds. The Raptor and TRX lean heavily into performance at the expense of genuine luxury and refinement. The AT4X, with its massaging seats, premium leather, Vanta ash trim, and full-suite digital cockpit, elevates the off-road experience into a genuinely premium category that its rivals struggle to match on the inside. It’s the truck for the person who wants to run the Baja 1000 in comfort and still be able to use the same vehicle to commute to a black-tie event.

The only real trade-offs—and they are minor considering its capabilities—are a slightly ponderous feel around sharp turns (it is a huge truck, after all) and a slight lack of aggressive lateral support in those comfortable, massaging front seats. But honestly, if I'm rock crawling, I'm doing it at a crawl, not taking a corner at 70 mph.

The 2025 GMC Sierra AT4X is a compelling argument that you can have it all: world-class off-road hardware like the DSSV dampers and dual e-lockers, massive V8 power (or colossal diesel torque), and a luxury interior that rivals high-end SUVs. It is a technical tour-de-force and, yes, an absolute joy to drive.

Tony Lesesne produces BEHIND THE WHEEL, exploring elite automotive technology and lifestyle. Based in South Florida, Tony is a passionate auto industry connector who blends technical analysis with his love for performance and value for auto consumers, offering a unique, entertaining perspective from an advocate and insider.