2021 Mercedes-Benz GLB vs 2021 Mercedes-Benz GLS

The third generation of the Mercedes-Benz GLS-Class, introduced in 2020 and carried over to 2021, evolved from the GL-Class, which debuted in 2006. Initially intended to replace the G-Class, the GL-Class instead found its niche among practical yet affluent customers, offering a luxurious, family-friendly alternative to the Navigator and Escalade. The GLS, with its softened angles and lines, appeared less bulky than its predecessors. Inside, it boasted a futuristic cabin dominated by a massive digital screen spanning nearly two-thirds of the dash, emphasizing its tech-centric controls. The GLS lineup included the GLS 450, GLS 580, and the high-performance AMG GLS 63, each offering a range of luxurious features and optional packages.

The 2021 Mercedes-Benz GLB, introduced in 2020, slotted between the smaller GLA and larger GLC in Mercedes-Benz's extensive SUV lineup. Despite its distinct measurements, the GLB shared a familial resemblance with its lineup-mates, featuring an attractive, athletic stance and a generous 7.9 inches of ground clearance. Inside, the GLB impressed with its modern design, highlighted by the repetition of round shapes across the dash and polished metal details in the HVAC vents. The single panel housing both the virtual instrument cluster and infotainment screen added to the cabin's elegance, while the beefy steering wheel with perforated leather grips provided a satisfying tactile experience.

The 2021 Mercedes-Benz GLS offered a range of powerful engines. The entry-level GLS 450 featured a twin-turbocharged 3.0-liter inline-six engine producing 362 horsepower and 369 pound-feet of torque. The GLS 580 upgraded to a twin-turbocharged 4.0-liter V8 with 483 horsepower and 516 pound-feet of torque. Both models used a nine-speed automatic transmission and Mercedes' 4MATIC all-wheel drive system. The AMG GLS 63, with its hand-crafted 4.0-liter twin-turbo V8, delivered an impressive 603 horsepower and 627 pound-feet of torque, achieving 0-60 mph in just 4.1 seconds and a top speed of 174 mph. All engines included Mercedes’ EQ Boost 48-volt mild-hybrid system, enhancing performance and efficiency. The GLS 63's adaptive air suspension and multiple drive modes provided a dynamic driving experience, while E-Active Body Control ensured a smooth ride.

The 2021 Mercedes-Benz GLB came with a single engine option: a turbocharged 2.0-liter inline four-cylinder producing 221 horsepower and 258 pound-feet of torque, paired with an eight-speed dual-clutch automatic transmission. Front-wheel drive was standard, with 4MATIC all-wheel drive available for an additional $2,000. The GLB's fuel economy was respectable, with EPA estimates of 23 mpg city/30 mpg highway/26 mpg combined for FWD and 23 mpg city/31 mpg highway/26 mpg combined for AWD. The GLB's performance was decent, with a 0-60 mph time of 6.9 seconds and a top speed of 130 mph. The 4MATIC version offered better handling and agility, making it a worthwhile upgrade for those seeking improved driving dynamics and off-road capability.

The 2021 Mercedes-Benz GLS featured three rows of spacious seating, accommodating up to seven passengers, with optional second-row captain’s chairs reducing capacity to six. The front and second rows offered ample headroom and legroom, while the third row, though less spacious, was still suitable for adults. The GLS provided 17.4 cubic feet of cargo space behind the third row, expanding to 42.7 cubic feet with the third row folded, and 87.4 cubic feet with both the second and third rows folded. The power-folding third row and numerous storage compartments added to its practicality.

The 2021 Mercedes-Benz GLB offered an optional third row, significantly impacting the second row and cargo space. The second row featured a 40:20:40 split seatback and a 40:60 split seat bottom, with each section adjustable for recline and slide. The third row, suitable for children or short trips for smaller adults, folded flat when not in use. The five-passenger GLB provided 27.0 cubic feet of cargo space behind the second row and 62.0 cubic feet with the second row folded. The seven-passenger version offered 5.1 cubic feet behind the third row, 24.0 cubic feet behind the second row, and 56.7 cubic feet with both rows folded. The front seats were highly adjustable and supportive, with available heated and ventilated options, while the second row comfortably accommodated two adults.

The 2021 Mercedes-Benz GLS came standard with the MBUX infotainment system, featuring a large touch screen and a trackpad controller. The system included Apple CarPlay and Android Auto, though a USB-C cable was required for connection. The MBUX voice-control system responded to commands with the phrase “Hey Mercedes,” offering functionality similar to Siri or Alexa. The digital dash extended to the fully-digital instrument panel, both controlled by touch-sensitive pads on the steering wheel, providing a customizable and user-friendly interface.

The 2021 Mercedes-Benz GLB also featured the MBUX infotainment system, with a 7-inch digital instrument cluster and a 7-inch touchscreen multimedia display. Standard technology included Bluetooth, Apple CarPlay, Android Auto, keyless start, and a power liftgate. The Premium Package upgraded the displays to 10.25 inches each and added keyless go. The optional Multimedia Package included navigation with augmented reality and traffic-sign assist. Additional available features included adaptive damping, 64-color ambient lighting, wireless device charging, parking assistance with surround view, active parking assist, and a head-up display.

The 2021 Mercedes-Benz GLS came standard with a comprehensive suite of driver-assistance features, including Active Brake Assist, forward-collision avoidance, rain-sensing wipers, blind-spot monitoring, and automatic high beams. Other standard safety features included automatic parking assist, a surround-view camera system, a driver-drowsiness monitor, and crosswind assist. Available safety tech included lane-keep assist, lane-change assist, adaptive cruise control, and a following-distance indicator. The GLS also featured a full array of airbags, traction control, self-tensioning seatbelts, and a tire-pressure monitoring system.

The 2021 Mercedes-Benz GLB benefited from Mercedes-Benz's reputation for safety innovation. Standard features included active brake assist, adaptive braking technology, crosswind assist, attention assist, and emergency call service. Available safety features included active LED headlamps, adaptive high-beam assist, and blind-spot assist. The Driver Assistance Package added advanced features like active distance assist Distronic adaptive cruise control, active steering assist, active brake assist with cross-traffic function, active speed limit assist, active blind-spot assist, active lane-keeping assist, and Pre-Safe Plus with Pre-Safe Sound. The GLB had not yet been rated by NHTSA or IIHS.