There’s a tiny niche that exists at the intersection of three-row crossovers, luxury cars, and muscle trucks, which is where the 2023 Mercedes-AMG GLS63 sits, rumbling threateningly. This ultra-SUV has the panache of an S-class sedan crossed with the soul of an AMG passenger car thanks to its 603-horsepower, 4.0-liter, twin-turbo V-8. While its overall size and shape are identical to the Benz-branded GLS-class, the AMG version comes with a specially-tuned air suspension that seasons it with a spicier on-road personality to go along with power that jams you into the seatback. We’d hardly call its moves race-car sharp, but it delivers more than a hint of AMG flavor on a twisty road. The cabin is richly appointed and the first and second rows are particularly spacious and similar to that of rivals such as the BMW X7 M50i. But if you’re looking for maximum interior space in your steroidal SUV consider the 682-hp Cadillac Escalade V-Series.
What’s New for 2023?
The AMG brand’s biggest bruiser rolls into 2023 with nary a change to its powertrain, chassis, styling, interior, or equipment.
Pricing and Which One to Buy
Although the GLS63’s starting price is deep into the six-figure realm, we’d still suggest a few options sure to please the whole family. For one thing, the Warmth and Comfort package is a nice bundle for those in northern climates, as it adds heated door panels, heated armrests, and a heated center console. We’d also suggest the Energizing package which includes the in-cabin fragrance diffuser and the Acoustic Comfort package, and also adds increased cabin insulation for a quieter interior. Mercedes-AMG also offers a host of standalone features that may catch your eye, including the bonkers 23-inch multi-spoke forged wheels that look just perfect when framed within the GLS63’s muscular wheel wells.
Engine, Transmission, and Performance
Under the hood of the GLS63 is a twin-turbocharged 4.0-liter V-8 engine that makes a whopping 603 horsepower with the help of a 48-volt hybrid system. All-wheel drive is standard, as is a nine-speed automatic transmission and air suspension. We were blown away by the GLS63’s performance at our test track as it out-accelerated several hot sports cars we’ve tested, tearing off a blistering 3.6-second zero-to-60-mph run. For comparison, the old GLS63—which made a mere 577 horsepower—managed a none-too-shabby 4.3-second zero-to-60-mph run. As impressed as we were with the GLS’s acceleration, we can’t say the same for its driving dynamics. The ride is firm, especially on the optional 23-inch wheels, but that firmness doesn’t translate to a feeling of unflappable precision when cornering, though it does offers plenty of grip to have some fun with on a twisty road.
Fuel Economy and Real-World MPG
The EPA estimates that the GLS63’s fuel economy is a dismal 14 mpg city and 18 mpg highway. On our 200-mile highway fuel-economy test route the GLS63 delivered a decent 22 mpg; the GLS63’s main rival—the BMW X7 M50i—managed 24 mpg in the same test. For more information about the GLS-class’s fuel economy, visit the EPA’s website.
Interior, Comfort, and Cargo
Three rows of seating and interior styling that’s slightly sportier versus the Benz-branded GLS-class sets the GLS63 apart from two-row SUV powerhouses such as the BMW X5 M and the Audi RS Q8. Like those competitors, the GLS63 is gorgeously appointed inside. Soft leather covers nearly every square inch of the cabin, and those areas that aren’t leather-wrapped are treated to genuine wood trim and tastefully applied meal trim; buttons and knobs are rendered in a rich-looking metallic finish. Front-seat occupants can enjoy a massage while blasting down the Interstate, and passenger space is generous in the second row, which can also be equipped with heated seats and power sunshades. The third row of seats is tight for adults but perfectly suitable for children. Cargo space is the same as the standard GLS-class, which in our testing fit four carry-on suitcases behind its third row and 30 in total behind the front seats.
Infotainment and Connectivity
The GLS63 comes standard with the same dual-screen infotainment setup found in the non-AMG variant. Two 12.3-inch screens, nestled next to each other in a shared bezel, form the digital gauge display and center infotainment display. Mercedes-Benz’s new MBUX interface can be controlled via voice, touchscreen, or with the clickwheel mounted on the center console. Apple CarPlay and Android Auto integration is standard, as is a 4G LTE Wi-Fi hotspot.
Safety and Driver-Assistance Features
Mercedes-AMG offers several driver-assistance features as standard, with more advanced features including a semi-autonomous driving mode. For more information about the GLS-class’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 automated emergency braking with pedestrian detection
- Standard lane-departure warning with lane-keeping assist
- Available adaptive cruise control with a lane-centering feature
Warranty and Maintenance Coverage
Mercedes-AMG’s standard warranty policies aren’t anything special. Furthermore, they offer zero complimentary scheduled maintenance, unlike BMW and Audi, which both offer such a perk.
- Limited warranty covers 4 years or 50,000 miles
- Powertrain warranty covers 4 years or 50,000 miles
- No complimentary scheduled maintenance
2021 Mercedes-AMG GLS63
front-engine, all-wheel-drive, 7-passenger, 4-door wagon
PRICE AS TESTED
$149,115 (base price: $133,095)
twin-turbocharged and intercooled DOHC 32-valve V-8, aluminum block and heads, direct fuel injection
243 in3, 3982 cm3
603 hp @ 6500 rpm
627 lb-ft @ 2500 rpm
Suspension (F/R): control arms/multilink
Brakes (F/R): 15.7-inch vented, cross-drilled, grooved disc/14.5-inch vented, cross-drilled, grooved disc
Tires: Michelin Pilot Sport 4S, F: 285/40R-23 (111Y) M01 R: 325/35R-23 (115Y) M01
Wheelbase: 123.4 in
Length: 206.4 in
Width: 79.9 in
Height: 70.2 in
Cargo volume: 17 ft3
Curb weight: 5927 lb
C/D TEST RESULTS
Rollout, 1 ft: 0.3 sec
60 mph: 3.6 sec
100 mph: 8.9 sec
130 mph: 16.0 sec
150 mph: 24.1 sec
Rolling start, 5–60 mph: 4.8 sec
Top gear, 30–50 mph: 2.9 sec
Top gear, 50–70 mph: 3.1 sec
¼-mile: 12.0 sec @ 115 mph
Top speed (mfr’s claim): 174 mph
Braking, 70–0 mph: 153 ft
Roadholding, 300-ft-dia skidpad: 0.92 g
C/D FUEL ECONOMY
Observed: 15 mpg
75-mph highway driving: 22 mpg
Highway range: 520 miles
EPA FUEL ECONOMY (C/D EST)
Combined/city/highway: 16/14/20 mpg
More Features and Specs