What Is It?
For decades, vehicle tuner AMG has been facilitating top-level performance modifications on Mercedes-Benz models, and the lineup of AMG creations has expanded considerably over the last few years. Mercedes first authorized AMG treatment for an SUV on the 1999 AMG ML55, one year after the ML’s debut. The GL (now GLS) joined the Mercedes-Benz lineup for 2007 as the full-size three-row option above the ML (now GLE), with the AMG version of the flagship Mercedes-Benz SUV joining in 2017. The third-generation Mercedes-Benz GLS debuted for 2020, with the 2021 Mercedes-AMG GLS 63 premiering for the new model year.
Mercedes-Benz provided us with a 2021 Mercedes-AMG GLS 63 finished in Selenite Grey Metallic at a starting price of $132,100. The test vehicle had additional options for a total price of $153,950, which includes a destination and delivery charge of $1,050. Options included 23-inch Matte Black AMG multi-spoke forged wheels, a carbon fiber engine compartment cover and a Burmester High-End 3D surround sound system. And at a price north of $150,000, the tester also came with a number of packages: Executive Rear Seat Plus, Warmth / Comfort, Energizing Comfort Plus, Acoustic Comfort and AMG Night.
Last year the Mercedes-Benz GLS received updated exterior styling including a bold front-end appearance upgrade. Further enhancements for the AMG 63 are a revised grille with vertical slats; an AMG body-color lower front fascia with large black air intakes; body-color side skirts and flared wheel arches; an AMG rear diffuser; a rear spoiler; and an AMG exhaust with dual rectangular twin outlets. The AMG Night package on the tester also added high-gloss black exterior trim, an AMG exhaust system and black chrome twin exhaust outlets.
Inside, the 2021 Mercedes-AMG GLS 63 feels like a sports car thanks to premium seats in Nappa leather with AMG badging, as well as an AMG Performance steering wheel in Nappa leather and DINAMICA with aluminum shift paddles. The test vehicle had an optional AMG Tartufo Brown / Black Exclusive Nappa leather interior with Metal Weave trim.
The 2021 Mercedes-AMG GLS 63 draws power from a 4.0-liter biturbo V8 engine producing 603 horsepower and 627 lb-ft of torque. Mercedes-AMG also adds an integrated EQ Boost starter-generator positioned between the engine, as well as an AMG SPEEDSHIFT 9-speed automatic transmission. The EQ Boost provides an additional 21 horsepower and up to 184 lb-ft of torque for a short period of time, and employs the starter motor and alternator for smooth start/stop functionality. EQ Boost also acts as a generator to provide power to the 48-volt electrical system. According to Mercedes-AMG, and after testing we believe them, the GLS 63 will accelerate from zero to 60 mpg in an estimated 4.1 seconds with an electronically limited top speed of 174 mph — numbers previously reserved for supercars.
AMG Dynamic Select
The 2021 Mercedes-AMG GLS 63 offers a choice of seven drive modes within the standard AMG Dynamic Select: Comfort, Sport, Sport+, Individual, RACE, Trail and Sand. The driver chooses from a range of settings to maximize performance capabilities, and AMG Dynamic adjusts a range of functions including engine responsiveness, transmission performance, suspension and steering.
AMG optimized every aspect of this SUV’s drivetrain for performance. Power gets delivered via an AMG SPEEDSHIFT 9-speed automatic transmission and AMG Performance 4MATIC+ all-wheel drive with fully variable torque distribution. The transmission delivers precise shifts with virtually no power interruption, and in Sport, Sport+ or RACE modes adds automatic double-declutch downshifts. An electronic locking rear differential combines with the Electronic Stability Program to maximize traction and optimal torque distribution.
The 2021 Mercedes-AMG GLS 63 suspension is based on AMG Ride Control+ air suspension with adaptive adjustable damping. Comfort, Sport and Sport+ settings are offered, and driving dynamics are improved with Active Ride Control — an active roll stabilization system with 48-volt power.
On the Road
The level of performance offered by the 2021 Mercedes-AMG GLS 63 is utterly amazing — although the numbers indicate sports car-level performance, the exterior appearance of an SUV might still cast doubts about such claims. That said, sliding into the driver’s seat feels like entering a high-performance sports car — even with the driving position a little higher off the ground. Pushing the button to fire the engine erases all doubts about performance. The rumble of 600+ horsepower puts a smile across face; sliding the gear selector into D transmits an instantaneous feeling of power.
Really Big and Really Fast
One of the biggest challenges when driving the AMG GLS 63 — it’s simply so fast. After a near-4-second zero to 60 mph time, and with a few more seconds hard on the accelerator pedal, the SUV will be at triple-digit speeds — enough to get drivers into trouble if not on a racetrack. Unfortunately, it’s hard to refrain from exercising a bit of pedal pushing because stepping on the accelerator is so satisfying — and it sounds so good.
While the raw acceleration of the 2021 Mercedes-AMG GLS 63 might be anticipated based on performance specs, the overall balance and driving dynamics are even more impressive. The SUV’s official curb weight has not been released, but an undeniable fact remains — this is a big, heavy vehicle and the engineering and technology to make it feel and drive like a sport sedan is remarkable. The AMG GLS 63 is great fun to drive with an incredible level of dynamic performance, yet it is also comfortable and can be as practical as needed. That said, GLS owners who live in areas of the country with wintry conditions will need to swap the 22-inch summer performance tires for smaller winter tires.
Starting at $132,100 and going north of $150,000 as tested, the AMG GLS 63 is in rarified air and will only be experienced by a few who have the means to purchase supercar performance in SUV packaging. But for those who have the choice, the AMG GLS 63 is a special vehicle — in many ways it is more akin to an AMG GT than a GLS 580.
Granted, the price of entry to the 2021 Mercedes-AMG GLS 63 is extremely high — and fuel consumption will be high was well. However, the levels of performance combined with the practicality of an SUV make this vehicle exceptional. The 2021 Mercedes-AMG GLS 63 would be easy to live with every day, and the fun-to-drive factor will never fail to put a smile on any driver’s face.