The 2021 Mercedes-Benz GLS is a full-size, three-row luxury SUV designed for families and drivers who want flagship-level comfort, technology, and road presence. Part of the current GLS generation introduced for 2020, the 2021 model continues with a refined cabin, strong turbocharged powertrains, and available air suspension for a smooth, quiet ride. It sits near the top of the segment against rivals like the BMW X7, Range Rover, and Audi Q7, emphasizing high-end materials and advanced driver aids. With generous space in all three rows and strong towing capability, it’s ideal for daily commuting, road trips, and upscale family hauling.

1) Engine lineup and performance: The 2021 GLS is commonly found as the GLS 450 with a 3.0L turbo inline-six featuring EQ Boost mild-hybrid assistance (typically 362 hp) and the GLS 580 with a 4.0L twin-turbo V8 with EQ Boost (typically 483 hp). Power is delivered through a 9-speed automatic transmission and 4MATIC all-wheel drive for confident all-weather traction. 2) Three-row seating and cargo room: Standard three-row seating makes it a true family luxury SUV, with power-folding options and versatile cargo configurations that suit strollers, sports gear, and luggage for long trips. 3) AIRMATIC and comfort tech: Available AIRMATIC air suspension helps deliver the “big Mercedes” ride quality many buyers seek, with adjustable ride height and improved comfort over rough pavement. 4) MBUX infotainment and driver assistance: The dual-screen MBUX setup, voice control, navigation, and available advanced driver aids (such as adaptive cruise control and lane-keeping features) make the 2021 GLS feel modern and easy to live with. 5) Towing capability: Properly equipped, the 2021 GLS can tow up to about 7,700 pounds, making it a strong choice for small campers, boats, or utility trailers in a luxury package.

Shoppers searching “2021 Mercedes-Benz GLS reliability” or “2021 Mercedes-Benz GLS problems” should know the GLS can be rewarding to own, but it’s also a complex vehicle with expensive systems. Commonly reported issues include: 1) Infotainment and electronics glitches: Some owners report MBUX screen freezes, random reboots, Bluetooth/CarPlay connection drops, or camera/sensor warnings. These can show up early in ownership (sometimes within the first 5,000–20,000 miles) and may require software updates, module resets, or sensor calibration. 2) Suspension-related concerns: Models equipped with AIRMATIC can experience air suspension faults such as uneven ride height, warning messages, or a harsh/floaty feel if a valve block, compressor, or air strut begins to weaken. These issues may appear more often as mileage climbs (roughly 30,000–60,000+ miles), and repairs can be costly. 3) 48V mild-hybrid/EQ Boost electrical issues: Because the GLS uses a 48-volt electrical system for its mild-hybrid functions, some owners report electrical warnings, battery/charging messages, or intermittent start-stop behavior. Diagnosis can involve the 48V battery, DC-DC converter, or related wiring, and symptoms may be intermittent. 4) Interior fit-and-finish and comfort complaints: Rattles, squeaks, or trim noises from the dash, doors, or third-row area are occasionally noted, especially on rough roads. While not always a “failure,” it’s a common quality-of-life complaint in a vehicle at this price point.