The GLS-Class is the largest, most luxurious SUV sold by Mercedes-Benz that displays what the automaker is capable of. Last year marked the debut of the redesigned, third-generation GLS-Class, and 2021 introduces two specialized variants: the ultra-luxe Mercedes-Maybach GLS600 and the 603-hp Autobahn special that is the Mercedes-AMG GLS63. The enormous Benz competes with other full-size three-row luxury SUVs including the Lincoln Navigator, Cadillac Escalade, and BMW X7.
The longtime flagship of the Mercedes-Benz stable has been the S-Class sedan, but the GLS serves luxury buyers who insist on an SUV. No surprise, this is an elegantly styled, generously appointed, properly luxurious three-row flagship. Even in the base trim, this cabin feels opulent. Third-row occupants will be a little cramped, though, and the second-row bench reclines forward for way-back access at a glacial pace.
Both the I-6 and V-8 powertrain options provide strong acceleration. The automatic transmission's shifts are more obvious than we'd like, though. Body control is excellent on the air suspension, but the GLS fails to deliver the magic carpet ride quality we'd expect from the S-Class of SUVs. The infotainment system can be tricky, too.
As a 2021 model, the GLS competed in our three-row luxury SUV comparison, finishing ahead of the BMW X7 but behind the Cadillac Escalade and Lincoln Navigator. Although it was easily the sportiest and best-driving of the group, the Benz's competitors offered more luxurious-feeling cabins, there wasn't as much space as you'd hope, and its high price tag was hard to swallow.
Sure, there are areas for improvement, but the GLS' stable handling, great engines, and luxurious interior come together for a compelling (if expensive) package. Factor in the new-for-2021 proudly antisocial AMG athlete and ultra-luxe Maybach variants, and this is quite a lineup.
The GLS-Class offers twin-turbocharged six- and eight-cylinder engines, with multiple states of tune for the V-8. Both engines feature Mercedes-Benz's EQ Boost mild hybrid technology. Every model pairs its forced induction engine with a nine-speed transmission and all-wheel drive.
Model: GLS450 4Matic
Engine: 3.0-liter turbo I-6 mild hybrid
Horsepower: 362 hp
Torque: 369 lb-ft
EPA fuel economy (city/highway): 19/23 mpg
Acceleration (0-60 mph): 5.8 seconds
Model: GLS580 4Matic / Maybach GLS600 4Matic / AMG GLS63
Engine: 4.0-liter twin-turbo V-8 mild hybrid
Horsepower: 483 hp (GLS 580) / 550 hp (Maybach) / 603 hp (AMG)
Torque: 516 lb-ft (GLS 580) / 538 lb-ft (Maybach) / 627 lb-ft (AMG)
EPA fuel economy (city/highway): 16/21 mpg (GLS 580) / 14/18 mpg (GLS 63)
Acceleration (0-60 mph): 4.1 seconds (GLS63)
Mercedes-Benz includes a handful of driver-assist active safety features on its flagship SUV. Automatic emergency braking, blind-spot monitoring, automatic high-beams, automatic parking assist, and a 360-degree camera system are standard on all models. Adaptive cruise control, cross-traffic braking, autonomous lane changing, and road sign recognition are optional extras.
Most GLS models seat seven passengers across three rows, with a three-seat second-row bench and two passengers across the third row. The GLS580 and AMG GLS63 can be ordered with second-row captain's chairs, dropping capacity to six, and the Mercedes-Maybach GLS600 is only available as a two-row with seating for four or five.
Legroom measures 40.3 inches up front, 41.9 inches in the second row, and 34.6 inches in the way back. In terms of cargo volume, the GLS provides 17.4 cubic feet behind the third row, but once you fold down the second- and third-row seats, that number swells to 84.7 cubic feet.
Every GLS features the dual-display dashboard implemented across the Mercedes-Benz lineup. In the GLS, it features two 12.3-inch displays for the instrument cluster and the touchscreen infotainment system. Apple CarPlay, Android Auto, and integrated navigation are included on all models, as is a wireless charging pad. Audiophiles will be pleased with the standard 13-speaker Burmester audio setup, and those who go all-out can spring for the 26-speaker Burmester system.