Pros
- 603-horsepower twin-turbo V8
- EQ Boost starter/generator
- Silky automatic restarts
- Active roll stabilization
- Air suspension w/active damping
Cons
- Pricey: It starts at $132,100
- Can exceed $150,000
- Thirsty
- Maximum of seven seats
What’s New this year?
- New AMG model
- Twin-turbo V8 has 603 horsepower
- 9-speed automatic transmission
- Air suspension w/active damping
- Active roll stabilization
People Also Ask
Where is the Mercedes-AMG GLS 63 built?
Like the GLE 63 S, the Mercedes-AMG GLS 63 is built in Alabama, using hand-assembled engines coming from AMG in Germany.
Is the Mercedes-AMG GLS 63 available with center-row bucket seats?
Yes, the GLS 63 is available as a 6-seater with center-row captain’s chairs, or as a 7-seater with a 3-seat center bench.
Is the Mercedes-AMG GLS 63 a hybrid?
In a way it is. The GLS 63 does have an electric motor/generator mounted between its engine and transmission. Although it generates 21 horsepower and 184 lb-ft of torque, this motor’s primary purpose is not to propel the car. Rather, the motor/generator assists take-offs, smooths upshifts and even controls the idle speed of the combustion engine. It’s also responsible for the smoothest and most immediate automatic restarts we’ve ever felt.
KBB Editors’ Overview
The 2021 Mercedes-AMG GLS 63 is a GLE 63 S that has been lengthened a foot and has a 5-inch-longer wheelbase. As a result, it boasts a 3rd-row seat for two, which means the GLS 63 holds up to seven — just what you might need for getting a couple extra kids to the soccer game. A 6-seat model, with luxurious center-row captain’s chairs, also is available.
Like the GLE 63 S, the GLS 63 is new for 2021, equipped with a new 603-horsepower 4.0-liter twin-turbo V8, adaptive air suspension and huge brakes. Built by AMG and fitted with twin turbos nestled in its vee, the engine is equipped with an integral starter/generator that assists take-offs, smoothens gearshifts and provides silky-smooth automatic restarts. The rumbly but refined powerplant also has an auxiliary electric compressor that supplements the turbos and eliminates any hint of lag.
A paddle-shifted 9-speed automatic transmission with a conventional torque converter directs power to all four wheels via a standard 4Matic all-wheel-drive system that can automatically send as much as 50 percent of the power to the front wheels to keep this luxurious 7-seat SUV moving in slippery conditions. What’s more, adaptive air suspension beautifully blends comfort and control, aided by six drive modes and active anti-roll bars made possible by the GLS’s standard 48-volt electrical system. Grippy 22- or 23-inch summer tires contribute further, as do monstrous brakes featuring 6-piston front calipers and massive 15.7-inch rotors.
All told, the 2021 Mercedes-AMG GLS 63 is a brutally fast family hauler that’s as easy to drive as a standard GLS 450, and it has all the quality, refinement and inherent safety you’ve come to expect of the Mercedes-Benz.
Driving the 2021 Mercedes-AMG GLS 63
With its 603 horsepower and 627 lb-ft of torque, the 2021 Mercedes-AMG GLE 63 S is an accelerative beast. It can hit 60 mph in a scant 4.1 seconds and reach an electronically limited top speed of 174 mph. Impressive, no doubt, but this power and performance don’t mean the GLS 63 is cantankerous around town.
On the contrary, the GLS 63 is a refined sweetheart of an SUV, easy in the daily grind and boasting all the practicality of a standard GLS 450. The automatic restarts of the fuel-saving stop/start system are almost unnoticeable, and six driving modes (Comfort, Sport, Sport +, Individual, Trail and Sand) allow the driver to configure the GLS as desired. In each, this big Mercedes SUV impresses, aided by natural-effort steering and brakes. The engine pulls with authority all the way up to its 7,000-rpm redline.
While comfortable on the highway, especially in Comfort mode, the GLS 63 belies its size on curvy mountain roads. The Sport model lowers the GLS by 0.4 inches, and body roll is practically eliminated by the standard Active Ride Control. Moreover, the rear-biased power delivery and standard limited-slip rear differential give this large SUV a truly sporty feel. Powering out of turns in a 3-row SUV has never felt this good.
Favorite Features
AMG ACTIVE ROLL STABILIZATION
Powered by the GLS’s 48-volt electrical system, Active Ride Control features an electromechanical actuator in each anti-roll bar that makes body lean in corners a thing of the past. Ride comfort in a straight line also is improved because one-sided bumps get balanced out.
AMG HIGH-PERFORMANCE BRAKES
A big vehicle needs big brakes, and the 2021 GLS 63 has huge ones. In front, the GLS 63’s drilled and vented 15.7-inch rotors are clamped by 6-piston calipers, while vented 14.6-inch discs are on duty in back.
2021 Mercedes-AMG GLE 63 S Interior
Thanks to a wheelbase stretched by roughly two inches over the previous-gen GLS 63, the 2021 Mercedes-AMG GLS 63 has a roomier interior. This is most noticeable in the middle row, which, when adjusted fully rearward, has 3.4 inches more leg room than before.
The GLS 63 dash is dominated by a modern high-res screen that spans much of the dash and features a 12.3-inch instrument cluster and an equally large touch-screen control panel. The instrument cluster has four available display styles (Modern Classic, Sport, Discreet, Supersport), and the leather-covered AMG sport seats feature generous bolstering without being confining.
As expected, materials’ quality inside is top-notch, and the stitched, leather-covered dash looks handsome with its numerous well-placed vents. Sixty-four available hues of ambient lighting add to the luxurious ambience.
The leather-covered 3-spoke steering wheel is from AMG. Thick of rim, it manages to incorporate numerous handy thumb controls without looking too busy. As in the GLE, there’s a leather-covered center console featuring two prominent grab handles and a control panel specific to AMG. The 6-seat GLS 63 that KBB recently sampled was equipped with the optional Executive Rear Seat Package, which includes a wide center console and a 7-inch tablet-style controller. While luxurious, the Executive package will set you back an additional $3,700.
2021 Mercedes-AMG GLE 63 S Exterior
This large Mercedes SUV looks like a long version of the GLE, with an AMG-specific radiator grille (with vertical chrome slats) that lets us know it’s an AMG GLS 63. Other unique bits include a new front bumper with a silver-trimmed splitter, a hood with twin power domes and standard active LED headlights.
As on the shorter GLE 63 S, the GLS 63 is adorned with rocker skirts, sideview mirrors and flared fenders done in body-color paint, and the stock wheels are 21-inch AMG alloys. Also available: 22- and 23-inch wheels, the latter shod with sticky 325/35ZR-23 Michelins. The rear view of the GLS 63 is highlighted by a strip of chrome trim between the taillights and a bumper/diffuser that houses twin dual-outlet tailpipes.
If you order the Night Package, the GLS 63 gets a sinister look courtesy of gloss-black exterior trim, anodized window trim, black-chrome tailpipes and matte-black AMG alloy wheels.
2021 Mercedes-AMG GLS 63 Standard Features
At its core, the Mercedes-AMG GLS 63 has some outstanding standard features: a twin-turbo 4.0-liter V8 with the EQ Boost starter/generator, a 9-speed automatic transmission, 4Matic all-wheel drive, monstrous brakes, an AMG locking rear differential and AMG suspension featuring air springs, active damping and the neat feature that eliminates body roll.
Standard comfort and convenience features include Nappa interior leather, heated and vented front seats, a panoramic moonroof, a fantastic Burmester sound system, a nav system, Apple CarPlay/Android Auto and wireless smartphone charging. Other standard fare includes the huge instrument panel/media display, plus 64 colors of ambient interior lighting.
This GLS 63 also has a generous standard safety suite. Besides automatic emergency braking, it has lane-keep assist and blind-spot assist, plus a system that senses if the driver is getting fatigued.
2021 Mercedes-AMG GLS 63 Options
Many options on the 2021 Mercedes-AMG GLS 63 are contained in packages. The most notable:
Executive Rear Seat Package ($3,700): massaging rear seats, a luxury center armrest with a 7-inch MBUX tablet, a storage compartment, two USB ports, wireless charging, luxury headrests and heated and cooled cup holders.
Warmth and Comfort Package ($1,100): a rapid-heating function, heated door center panels, heated front and rear armrests, and a heated center console.
Acoustic Comfort Package ($1,100): increased cabin insulation, infrared-reflecting film on the windshield, acoustic and infrared-absorbing film on the side windows.
Night Package ($750): black trim on the front fenders, rear apron, tailpipes, front splitter, window frames and roof rails.
MBUX Technology Package ($1,450): augmented video for navigation and a head-up display.
Individual options include a carbon-fiber engine cover ($1,500), 23-inch forged AMG wheels ($4,950), and Burmester High-End sound system ($4,550).
2021 Mercedes-AMG GLS 63 Engine
Although the previous GLS 63 was equipped with a twin-turbo 5.5-liter V8, the 2021 model is powered by a twin-turbo 4.0-liter V8 that puts out 603 horsepower and 637 lb-ft of torque. That’s 26 more horsepower and 66 more lb-ft than the previous-gen GLS 63.
The aluminum-block engine, which has turbos inside its vee-shaped block, also boasts intelligent-cylinder management. This means that cylinders two, three, five and eight are shut down in light-load situations (like cruising down the highway) to save fuel. A graphic on the dash illuminates when you’re in 4-cylinder mode.
Also notable: The 4.4-liter V8 features an integral 48-volt starter/generator. This 21-horsepower electric motor, mounted between the GLS 63’s engine and 9-speed automatic transmission, assists with take-offs, smoothens gearshifts and even controls the idle speed of the internal-combustion engine. It also powers the water pump, the power-steering pump and the air-conditioning compressor.
4.0-liter twin-turbocharged V8
603 horsepower @ 5,750-6,500 rpm
627 lb-ft of torque @ 2,500-4,500 rpm
EPA city/highway fuel economy (estimated): 15 mpg/19 mpg
How Much Does the 2021 Mercedes-AMG GLS 63 Cost?
The 2021 Mercedes-AMG GLS 63 goes on sale this summer with a Manufacturer’s Suggested Retail Price (MSRP) of $132,100. With all options and the $995 destination fee included, the GLS 63 that KBB recently sampled had a final price of $153,035.
Some of the pricier options included forged 23-inch AMG wheels ($4,950), a Burmester Surround Sound stereo ($4,550), the Executive Rear Seat Package ($3,700), and a carbon-fiber engine cover ($1,500).
For some pricing perspective, consider that the 3-row BMW X7 M50i, which is powered by a twin-turbo 4.4-liter V8 with 523 horsepower, starts at $99,600. In case somebody’s measuring, the largest wheels available on the X7 M50i are 22s.
Always check the KBB Fair Purchase Price to see what other people in your area are paying for their 2021 Mercedes-AMG GLS 63. Resale values traditionally are strong for Mercedes.
Which Model is Right for Me?
2021 Mercedes-AMG GLS 63
603-horsepower twin-turbo V8
EQ Boost starter/generator
4Matic all-wheel drive
AMG seats w/Nappa leather
Massive 6-piston front brakes
2021 Mercedes-AMG GLS 63 Safety Technology
Active Driving Assistant
Standard on the 2021 GLS 63, Active Driving Assistant includes active cruise control (with Stop & Go) and Active Steering Assist, which automatically keeps the big SUV in its lane, even if it’s not well marked.
Active Blind-Spot Assist
One of our favorite safety aids, Blind Spot Assist lets you know when there’s a vehicle in the GLS 63’s blind spot, making lane changes much safer.
Attention Assist
With this standard program, the GLS 63 monitors steering movements and several other parameters to determine if the driver is tired or possibly falling asleep. Audible and visual alerts will let the driver know it’s time to take a break.
