2024 Mercedes-AMG GLS63 First Test: Massively Impressive—With One Downside

See All 23 Photos23

There’s a galactically massive, extinction-level event coming for the automotive industry. When it finally occurs and the gas-swilling dinosaurs die off for good, we’ll look back at vehicles like the 2024 Mercedes-AMG GLS63, the go-fast model in Benz’s GLS-Class SUV lineup, in much the same way as we do a T. rex—with reverence and awe.

That’s because the recently refreshed 2024 Mercedes-AMG GLS63 is huge and fierce, an apex predator of an SUV with incredible power that can devour any road in its path. And its appearance is brutally impressive, a mean, mugging monster in a top-shelf tuxedo. But there’s a downside to the GLS63’s fury and fire, because like the T. rex, it won’t be able to adapt when the comet hits. It’s too heavy and inefficient to survive.

Super Quick, Super Nannied

Until that day arrives, however, we’ll continue to marvel at how Mercedes-AMG has managed to motivate the three-row, nearly three-ton GLS63 to achieve stupid-quick numbers like the ones we recorded, namely a 0–60-mph time of just 3.7 seconds and a quarter mile of 12.1 seconds at 114.5 mph. Those results are virtually identical to a mechanically similar GLS63 we tested in 2021. The only other three-row SUV in recent memory that could even approach these numbers was a BMW Alpina XB7, which we also tested in 2021 (0–60 in 4.0 seconds, quarter in 12.4 seconds at 114.0 mph).

The thunder under the GLS63’s hood still comes courtesy of AMG’s handcrafted 4.0-liter, twin-turbo V-8, slightly boosted by a hybrid assist system to produce 603 hp and 627 lb-ft of torque. There’s no launch control system for the big Benz SUV, so we turned the dial up to Sport+, overlapped the pedals to around 2,500–3,000 rpm, and then let it off the chain as all four wheels spun up and sped off.

See All 23 Photos23

What a note from the V-8. It’s one of the greatest-sounding engines under full throttle in the modern era and is unquestionably one of the key reasons you’d buy the GLS63 in the first place. There are already Mercedes electric vehicles that make more horsepower and torque, but they’ll never match the sonic symphony the biturbo-eight offers as it upshifts brutally through the AMG-massaged nine-speed automatic transmission. Almost as impressive is how well the GLS63 stops from 60 mph, with a shortest distance of just 107 feet (the one we tested in 2021 did it in 110 feet, with the XB7 doing it in an amazing 100 feet).

Unimpressive, however, is how the big AMG Benz handled itself in our dynamic tests. Back in 2021 when we tested the earlier GLS63 and the XB7, both of those behemoths recorded super sports-car-esque numbers, with the GLS63 whirling around the skidpad at a 0.92 g (average) and our figure-eight test in 24.9 seconds at 0.78 g (average). We achieved 0.95 g (average) and 24.8 seconds at 0.78 g (average), respectively, in the XB7. For the 2024 Mercedes-AMG GLS63, the driver aid nannies intervened and rapped it hard on the knuckles. Our test team complained loudly about electronic interference. (Mercedes officials told us traction control is now always on to a certain degree and cannot be fully defeated.) The numbers suffered as a result, dropping precipitously to just 0.77 g (average) and 27.7 seconds at an average of 0.65 g. Keep in mind, the 2021 and 2024 models are roughly the same in their powertrains and suspension setups.

In reality, will anyone ever really track a GLS63? Well, maybe. This luxury super SUV is equipped with AMG’s TRACK PACE feature with Race and Drag Race options. So yeah, you may, given that AMG offers these options for it and loudly boasts of its cornering abilities. We took it to the track, and the results were less than amazing—at least when the going got extra twisty.

See All 23 Photos23

Super-Luxurious, Super-Thirsty Superstar

For the overwhelming majority of 2024 Mercedes-AMG GLS63 buyers who won’t track their super Benz SUV, they get what they pay for at $147,000 to start. That means a luxuriously appointed, feature-rich, and versatile vehicle. Drive it the way most will, in Comfort mode (the new AMG steering wheel lets you dial it up to Sport or Sport+ modes easily), and the GLS63 behaves like the rest of the GLS-Class lineup: as a topflight people mover.

Thanks to its updated and now standard AMG Ride Control + suspension system, Mercedes claims the GLS63 is more comfortable in a straight line, with a bigger spread between the comfort-oriented and sportier settings. Indeed, over several days of typical around-town travel, the SUV wasn’t jarring over significant road imperfections in the base Comfort mode. It’s also one of the better-handling large SUVs we’ve driven from a steering perspective, with a heavy, extremely direct feel. Ride Control + is also programmed to mitigate body roll, and indeed, during normal, everyday road driving, it performs admirably. Our only real complaint is a touchy throttle response from a stop. It takes more than a bit of massaging to get off the line without some bucking behavior.

It’s also about as haute as a GLS-Class SUV gets from an interior packaging perspective, save the super-lux Maybach GLS. This test model came in six-seat configuration, with electronic seat adjustments in the second-row captain’s chairs, including the ability to move it for third-row access at the touch of a button. It has all the whizbang gadgets and gizmos with which to dazzle your friends and family (the family we carted around was duly dazzled), like massaging front seats as part of the high-style brown and black Nappa leather setup, a huge panoramic roof, adjustable digital lighting and instrument panels, an MBUX software upgrade, and much more.

Outside, mighty matte-black forged 23-inch rims (a $5,150 option), red brake calipers, and the special-to-the-GLS63 Twilight Blue Metallic sheen help set this particular vehicle apart from its tamer GLS brethren.

One thing you likely won’t dazzle anyone with (at least not in a positive way) is the GLS63’s paltry fuel economy. At 14/18 mpg city/highway, it simply devours dino juice. We’re guessing this isn’t a huge concern for people who can afford this vehicle, but it is increasingly so for the rest of the world (and Mercedes) as the paradigm shift accelerates. Until their day comes, though, we’ll continue to remain enthralled by the performance of maniacal people-moving machines like the 2024 Mercedes-AMG GLS63.

See All 23 Photos23