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2021 Mercedes-AMG GLS63: A 603-HP Luxury Tank Conquers a Winter Road Trip

A visit to the Michigan Upper Peninsula taught us a few things about this high-tech family bruiser.

byJerry Perez|
Mercedes-Benz Reviews photo


I grew up in Mexico City, one of the most populated and congested cities in the world. Later, I lived in San Antonio, Texas; also a booming and crowded metropolis in its own right. It's evident that cold, icy, snowy, rural-ish conditions weren't part of my upbringing, and neither was driving in them. That didn't happen until I moved to rural Michigan in my mid-20s and experienced commuting on snow-covered roads for the first time.

It was a Pontiac Sunfire that gave me my Winter Driving Baptism by Fire. (Or Ice, I guess.) I understeered, I oversteered—but mainly understeered—and I spun off the road, but I logged many nail-biting miles in that cheap-tastic coupe. I'll never forget driving down Michigan country roads playing a rather dangerous game of "where did the road go? It was just there, but now all I see is snow!" It was a far cry from anything I had experienced, but there were some upsides to my rather abrupt introduction to The Great White North.

Jerry Perez

That Sunfire taught me almost everything I know about winter driving. It taught me to be gentle with the pedals, smooth with the steering, leave an extra-long gap to the car in front, and something I had already learned in karting: always keep your eyes far down the road and not directly in front of you. The further down you see, the more time you have to react to a situation. It also taught me to never let my fuel drop too low just in case I got stranded, and to carry basic tools to help with repair or recovery in inclement weather.

The trusty Sunfire is long gone but that wintry weather still comes around once a year, helping me keep those winter-driving chops sharp. When a 603-hp 2021 Mercedes-AMG GLS 63 was dropped off at my doorstep, complete with 22-inch Pirelli winter tires, my family—who apparently haven't had enough snow this year—quickly bullied me into putting those skills to good use once again. Those darn kids, always so convincing.

The test: Michigan's Upper Peninsula.

2021 Mercedes-AMG GLS63, By the Numbers

  • Base Price (As Tested): $132,100 ($150,445)
  • Powertrain: 4.0-liter twin-turbo V8 with 48-volt hybrid system | 603 horsepower, 627 pound-feet of torque | nine-speed automatic transmission | all-wheel drive
  • Max Towing Capacity: 7,500 pounds est.
  • Max Payload Capacity: 1,565 pounds est.
  • EPA Fuel Economy: 14 city | 18 highway | 16 combined
  • Cargo Volume: 42.7 cubic feet (16 with third row up)
  • The Premise: A three-row SUV that can do zero to 60 in just 4.1 seconds while coddling its passengers with the ultimate in luxury and tech.
  • Quick Take: It's fast, it's smart, it's comfortable, and it's very expensive. It's also borderline perfect.
Jerry Perez

You may not realize just how far north that area actually is, but it is pretty far north, landing several hundred miles northwest of Toronto, Canada. Needless to say, they get some rowdy weather.

Even in my line of work, it's not often that a $150,000 luxury SUV lands on my driveway, so right away this felt like a high-stakes road trip. The GLS 63 sat at the top of the Mercedes food chain up until it was dethroned by the also GLS-based Mercedes-Maybach SUV late last year. Some would argue that the Bentley Bentayga eclipses the GLS in terms of panache, but the Bentayga doesn't offer three rows of seating like the GLS, and even the W12 model comes three horses short of the AMG's 603-hp output. The same goes for any Porsche or Maserati offerings. Lower in the nobility spectrum, the three-row Dodge Durango Hellcat actually beats the AMG by 100 ponies, but doesn't come anywhere near it in terms of... well, everything else.

The only SUV that can match the GLS63's chops is the BMW Alpina XB7, which is propelled by a 612-hp turbo V8 that launches the 5,860-pound  German from zero to 60 mph in just 4.0 seconds flat—that's one-tenth faster than the AMG, but produces 590 pound-feet of torque compared to the AMG's 627. I haven't driven it, but if it feels as utterly disconnected and cyborg-like as the BMW M8 Competition I recently drove, I know which family ride I'd buy with my newfound GameStop cash.

Jerry Perez

In a nutshell, I had one of the if not the biggest and baddest three-row SUV at my disposal, and where was I headed? A snowy, slippery place where horsepower and speed are utterly useless.

No Sleep 'Til the UP

The route consisted of a 10-hour drive (with optimum road conditions) starting in Indianapolis, heading straight north through Chicago, Milwaukee, and Green Bay into the Upper Peninsula. With the forecast showing freezing rain in northern Indiana and then heavy snow in southern Wisconsin, we hit the road in the wee hours of the morning to try and beat the worst of it. With tools like a recovery strap, foldable shovel, road flares, and other emergency supplies like hand-warmers and snacks packed in the trunk, we hit the road just as temperatures began to dip into the teens.

Google Maps
Jerry Perez

Like all modern Benzes, the GLS63 isn't short on technology. As the S-Class of SUVs, my tester had all the performance and driving aids you could imagine, as well as all the comfort, luxury, and entertainment options offered from the factory. This made me feel happy and worried at the same time. It felt great to know that we were rolling in what's essentially a luxury tank, but it's no secret that technology often fails, and when it does, it's usually at the worst time possible. Where we were headed, the nearest dealership was 250 miles away, so "popping in for a little fix" or getting a tow down the road wasn't exactly an option.

The first couple of hours on the road were all about getting accustomed to the GLS's features and overall behavior. You learn a lot about a car as you cruise through the interstate in the dead of night, especially when the rest of the occupants are asleep and the radio is off. It was just me and a $150,000 AMG silently devouring miles. The 6,017-pound SUV felt like an apartment building gliding down the road, with its intelligent LED headlights lighting the way in a manner that can only be described as absolutely incredible.

When the low beams were doing the job, I could visually notice how the light beam constantly adjusted itself to make sure I always had the absolute best view of the road ahead of me; not the highway signs above me or to my right, not the incoming traffic, and not the patch of asphalt ten feet in front of me—but directly into the horizon in a sharp and well-defined zone.


Then there were the automatic high beams, which when activated, triggered a Cirque du Soleil-style light show that literally made me smile every time. Unlike other high beams, these don't just go, BAM! NOW YOU'RE BLIND FROM THAT REFLECTIVE HIGHWAY SIGN HAHAHAHA. 

No, the jewel-like LED beams turn on in a sequential pattern that you can actually see reflected on trees, walls, or whatever objects are next to you as you're driving down the road. When no longer needed, the high beams transition back to low beams in an equal manner, slowly fading away until the regular lights take over. It's not a sudden switch, and that's actually quite easy on the eyes. The best way to describe this is that when the high beams are on, you don't exactly see more, you just see better. Remember when you switched from Standard Definition to High Definition TV? It may sound weird, but it's kind of like that.

Earlier on, I had activated the pre-programmed Slippery/Snow driving mode with the hopes of taming all 603 horses under the hood as much as possible. I had also individually adjusted the active exhaust system to be on quiet mode as to not disrupt the sleeping kiddos in the back, and adjusted the suspension to its softest setting for better grip and comfort. There was no doubt that this was a long-range cruiser, basically a grand tourer SUV.


About four hours in, it was time for our first pit stop and the AMG's turn to do its favorite thing: get fuel. Roughly 24 gallons of the premium stuff is what it took to fill up the beast, which even with temperatures in the single digits had managed to deliver about 17 mpg during our first stint—just one mpg off its EPA-estimated figure.

During the second stint behind the wheel, from Kenosha, Wisconsin up to Green Bay, I felt much more at home behind the "surfboard-style" two-foot-long gauge cluster/infotainment screen. More importantly, my bum was enjoying the heated (and ventilated) massaging seats. But while I was being treated to a simulated hot stone massage and the infotainment screen simulated cozy fireplace complete with sparks and crackling sounds, my hands were actually rather cold. That's because someone at AMG thought it'd be ok to make the optional $900 Alcantara and carbon fiber steering wheel incompatible with the heating element found in the standard steering wheel. So while even the front and rear armrests, and even the door panels were heated, the steering wheel wasn't.

I can see it in my mind; a wealthy Connecticut man checking every box of his new AMG, only to realize on the first cold day of the year that his $150,000 luxury family SUV doesn't have heated steering. What a dumb wheel for a big passenger car.

Jerry Perez
Jerry Perez
Jerry Perez

With gloves on hands, we continued north along the western edge of Lake Michigan as the sun began to rise. With the kids awake now, the cabin was lively with laughter and the occasional sibling tussle. I turned on the kid-friendly comedy channel on Sirius XM radio, which wasn't as lame as I remembered, or I'm just old now and I laugh at bad dad jokes. The Burmester surround sound did its job of delivering solid sound, whether it was comedy or the occasional Metallica to stay awake, though it wasn't exactly anything out of this world. A nice luxury, sure, especially in the middle of nowhere.

Welcome to Green Bay

By now the worst of the weather was behind us and sunshine made the snow sparkle as if fields were covered in Swarovski crystals. At each stop—and there were many—it was always the same thought in the back of my head: if something goes wrong out here, we're screwed. It was now below zero when you factored in the windchill and the front and rear ends of the car were absolutely caked in snow, salt, and road grime. We'd been running the engine non-stop for over eight hours, including a power nap where I idled the motor to keep the heater on. And let's not forget, interstates aren't exactly a walk in the park during this time of year, blasted with potholes and dirty slush that splashes into the engine bay and bathes components in salty gunk. All of that came on top of the overall stress of running a high-performance machine in frigid temperatures, but so far it was just business as usual for the GLS. Even the sensors and cameras, which I expected to bow out early on due to the road grime, were actually still functioning properly.

The mighty GLS soldiered on with its head held high into Green Bay.

Jerry Perez
Jerry Perez
Jerry Perez

Now, I don't watch football, and I honestly could care less about who can throw, kick, or carry a ball around while avoiding being tackled by large men, but even I can get excited about a cool stadium, so when in Rome... visit Lambeau Field, home of the Green Bay Packers. A few areas typically open to the public were restricted due to the pandemic, but you could still walk around the enormous bowl and check out some of the action. If you're in the area, it's worth a few minutes of your time.

From Lambeau, we drove to a local-favorite breakfast joint that promised larger-than-life pancakes. And lemme just say, the locals weren't wrong. The pancakes were about the diameter of the GLS' front brake rotors (15.7 inches) and stacked up high with strawberries and whipped cream. This other Midwestern Gem on the menu was essentially a mountain of potatoes, roughly the size of a steering wheel, topped with what seemed like pounds of gravy and sausage. But unlike my steering wheel, however, these were pipin' hot.

A couple of hours later we finally crossed into Michigan's Upper Peninsula. The UP at last. Almost immediately, there was plenty of snow on the ground to really justify those pricey specialty Pirellis we were rolling on. And during some roadside stops, they worked together with the 4matic all-wheel-drive to make sure we didn't get beached in tight-packed snow. 

The rest of the drive was a combination of snow and ice, though the Active Ride Control (which is powered by the 48-volt electrical system) used its electro-mechanical actuators on the front and rear axle to keep things balanced and in check. Where this system would keep things stiff during sporty driving in dry conditions, this time it actually softened things to maintain maximum traction. This didn't keep me from blurting out the occasional oh shit! every time the traction control light flashed in front of me, but thankfully the situation never escalated.

After 11+ hours on the road, we had reached our cabin. It was time for the GLS to rest and all of us to setup inside and get some rest. So far we had traversed 600 miles, crossed from the Eastern Time Zone into Central and then back into Eastern again, driven through freezing rain, sunshine, snow, ice, visited a football field, and eaten more carbs in one sitting than we typically do in an entire day. Great success.

Jerry Perez
Jerry Perez

Over the next several days the GLS played the role of an expensive, uber-powerful, family hauler that was used and abused and driven on everything from salt-covered roads to unpaved trails caked with 10+ inches of snow. Between the kids getting in and out with snow-covered boots, sleds getting thrown into the trunk, and even serving as a sort of mobile dining room thanks to restaurants being closed due to the pandemic, the GLS63 did it all. Heck, we even helped tow a VW Beetle out of a ditch after its teenage driver slid off the road. That's why you always carry a tow strap, kids!

Despite the constant abuse, every single component of the Benz performed as expected. And during seemingly never-ending two-lane straights, I was even able to get a little taste of the V8's power to do some passing. A quick two or three taps of the left paddle and the nine-speed transmission would prime the GLS to lunge forward with violent force, while the 48-volt EQ Boost system injected an additional 21 horsepower—as if they were needed.

Sure, I didn't exactly cross the entire continent in subzero temps while escaping a zombie apocalypse, but believe it or not, sometimes you don't have to do half of that to get a car's weaknesses to show through. Sometimes all you have to do is get a fidgety child to poke and prod to find out how many interior body panels can come off an Alfa Romeo. True story.

Jerry Perez
Jerry Perez

Goin' Back to Indiana

As it turns out, things wouldn't be so pretty and pink toward the end of our trip, with harsh weather moving across the region just as we were supposed to embark on our drive home. In fact, things got so nasty that we had to resort to driving two hours east only to head south through Michigan's lower peninsula rather than drive the original way back. This not only added more time and mileage to our trip but also forced us to drive on—how do I put this?—um, shitty roads not kept up by Michigan road crews.

Perhaps the only upside to our new route was the fact that we'd get to cross the Mackinac Bridge, which is always a great thing to experience. The roughly five-mile-long suspended bridge connects Michigan's lower peninsula to the UP and is often shut down due to strong winds and nasty winter weather. Luckily, this time said weather was west of us, so we crossed into the mainland without any issues. Sadly, it was so gloomy that we couldn't see Mackinaw Island to the left of the bridge.

Conditions got a bit sketchy through central Michigan, but they were safer than on the other side of the lake. Plus, I can now say that I've done the full loop around Lake Michigan, and that's always been on my bucket list, per se.

Jerry Perez

After a couple of meals on the go and some more fuel for the thirsty AMG, we arrived safely at home with what's easily the filthiest vehicle I've ever been in. The road grime was real and the interior was just awful. A serious wash was on order.

Reflecting on our trip, I find it amazing that our plan went off without a hitch—minus the last-minute route change on the way back. Despite the frigid weather, slippery roads, and an SUV so technologically advanced that it made me fear for its fragility in harsh climates, everything had gone accordingly and the GLS was intact.

What We Learned

The big takeaway? Well, there's more than one. First, always carry the right tools for the job and expect the unexpected. For example, my wife loves to travel in comfy shoes and there's nothing wrong with that, but if you're in the middle of winter where it snows, also bring a pair of boots. Don't get caught having to hike out of a ditch in house slippers.

Jerry Perez

Second, take it easy. Driving in snowy or icy conditions isn't rocket science, and while there are techniques to develop with practice, they all start with taking it easy. Slow down and leave a huge gap to the car in front. These two tips alone can help save lives.

Third, over-engineering matters and the GLS 63 AMG is living proof of that. Demanding scenarios like our road trip truly put build quality and reliability to the test. Whether it's blasting down the Autobahn at 170 mph, off-roading in Death Valley, or hauling messy children to the Great White North in subzero temps, building a car to exceed expectations rather than just meet them is the difference between getting to your destination and getting stranded on the way to.

Finally, the GLS isn't just Mercedes-Benz's (almost) flagship, but it's ostensibly the flagship of the entire SUV spectrum. It is what a luxury SUV should be and what its competitors should aspire to become. No more and no less. $150,000 is a steep price to pay for perfection, of course it is, but that's also the very top of the GLS spectrum. A GLS 450 with a 362-hp turbo inline-six costs around $80,000, and a GLS 580 with all the goodies and a 483-hp biturbo V8 is about $115,000. That's $35,000 less than the 63 and you still get 90 percent of the experience.

Call it a family SUV, a grand touring SUV, or just an overpowered German SUV for well-off soccer moms and baseball dads who find themselves in traffic court a lot, it doesn't matter. It's still the best damn SUV I've ever driven, full stop.

UPDATE 2/25/21: A Mercedes spokesperson reached out to me to explain that while my specific test vehicle did not feature a heated steering wheel, it is possible to customize a carbon fiber steering wheel with a heating element. In a nutshell, it comes down to the "AMG Drive Unit," which are the configurable steering wheel buttons located on either side of the wheel’s center lower spoke. You can essentially choose to have these and not a heating element, or the other way around, but not both. It's all a matter of preference, and in this case, the test vehicle was equipped with the buttons.

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