The 2021 Mercedes-Benz CLS-class is a mid-size luxury sedan posing as a coupe with four doors and sharing bits with the brand’s excellent E-class sedan. While the CLS has swoopier exterior styling and a different interior design than the E, its back seat and trunk are less accommodating. Still, every version has a speedy 362-hp, turbocharged inline six-cylinder engine, an obedient automatic transmission, and a graceful ride quality. Of course, it wouldn’t be a Mercedes without an upscale cabin that has rich materials and a roster of deluxe features, such as massaging front seats and voice-control software that uses artificial intelligence. The 2021 CLS450 is outgunned by its sportier cousin, the Mercedes-AMG CLS53 (reviewed separately), but it delivers all of the class offered by the regular E-class sedan, plus slinky good looks.

What’s New for 2021?

Mercedes enhances the technology on the 2021 CLS-class by fitting it with the company’s latest infotainment system and updated driver assists. The former materializes through the addition of the Mercedes-Benz User Experience (MBUX), which boasts predictive functions and is available with navigation that features augmented reality. Likewise, the new touchscreen display uses a large touchpad on the center console versus the old infotainment system’s rotary controller. Every CLS also now comes with a 12.3-inch digital gauge cluster. The sedan’s standard automated emergency braking now recognizes oncoming traffic, and its adaptive cruise control now responds to live-traffic data.

Pricing and Which One to Buy

• CLS450: $71,000 (est.)
• CLS450 4Matic: $73,500 (est.)

The CLS450 comes in only one trim level. Those who want extra oomph should entertain the more entertaining CLS53, but it costs about $11,000 more to start. However, that AMG version comes standard with 4Matic all-wheel drive, an option that tacks $2500 onto the regular Benz. We’d skip the latter on our preferred CLS450, which has rear-wheel drive and desirable standard features. These include a 12.3-inch digital gauge cluster, blind-spot monitoring, customizable ambient lighting, hands-free passive entry, leather upholstery, and heated front seats. We’d up the luxury quotient with the Premium package that brings a fantastic Burmester audio system and wireless charging—and unlocks fancy individual options, such as massaging front seats and ventilated front-seat cushions. We’d also choose the head-up display, soft-close doors, and three-zone climate control. The optional air suspension provides a more serene ride, and the Driver Assistance package has modern assists (adaptive cruise control and lane-keeping assist) that are hard to pass up.

Engine, Transmission, and Performance

With the CLS-class, buyers can choose between two engines. Both the CLS450 and CLS450 4Matic come with a turbocharged 3.0-liter inline-six paired with a 48-volt hybrid-assist system called EQ Boost. The setup provides output of 362 horsepower and 369 lb-ft of torque. This powerplant got the CLS450 from zero to 60 mph in a crisp 4.7 seconds at our test track. A nine-speed automatic transmission handles gear shifting duties. Five driving modes are standard—Eco, Comfort, Sport, Sport Plus and Individual—and this allows you to customize the car’s performance to suit your preferences. With the CLS450, the feel from behind the wheel is smooth and calm, never frenetic.

Fuel Economy and Real-World MPG

While the EPA hasn’t released fuel-economy estimates for the 2021 model, we don’t expect the figures to differ from last year. The government rated the 2020 CLS450 at up to 24 mpg city and 31 highway. Adding 4Matic all-wheel drive drops each number by 1 mpg. These ratings make the Mercedes a more fuel-efficient choice than the Audi A7, which is rated at 22 mpg city and 29 highway. But that’s on paper. We tested both models on our 200-mile highway route, which allows us to evaluate real-world mpg, and the CLS450 4Matic and A7 each earned an impressive 36 mpg.

Interior, Comfort, and Cargo

The polished planes and sloping lines of the CLS-class’s exterior are reflected in its cabin design. The dash encircles front-seat passengers with a graceful swirl, and a quartet of circular air vents dominate the center stack. With its nappa leather upholstery, the overall look of the cabin is premium and undeniably glamorous. There’s seating for five, but the car’s swooping roofline takes a toll on headroom for those perched in the back. The CLS-class provides 35 inches of rear-seat legroom. That’s two inches less than you’ll get with the A7. Despite this Benz’s sizable footprint, there’s not a whole lot of room in the trunk. Cargo capacity measures in at a paltry 12 cubic feet. In comparison, the A7 serves up 25 cubic feet of room for your belongings.

Infotainment and Connectivity

The base-model CLS-class comes with Bluetooth phone connectivity and streaming audio, and Apple CarPlay/Android Auto smartphone integration is on hand to help you seamlessly connect your devices. The infotainment system features a 12.3-inch display and a touchpad controller. The list of optional equipment includes a Wi-Fi hotspot, a head-up display, and wireless device charging.

Safety and Driver-Assistance Features

The 2020 Mercedes-Benz CLS-class hasn’t been crash-tested by the National Highway Traffic Safety Administration (NHTSA) or the Insurance Institute for Highway Safety (IIHS). Still, the CLS450 comes with standard and optional driver-assistance technology. Key safety features include:

• Standard forward-collision warning and automated emergency braking
• Available adaptive cruise control with stop-and-go technology
• Available lane-departure warning and lane-keeping assist

Specs