2021 Mercedes-Benz S-Class vs 2021 Kia K5

The 2021 Kia K5 marked a significant evolution in Kia’s design language, reflecting the brand's shift from producing mundane sedans to more dynamic and stylish vehicles. The K5 broke away from Kia's past, embodying a bold and sophisticated aesthetic. Styled in GT-Line trim with a striking Wolf Gray paint and red seats, the K5 resembled the chic Audi A5 Sportback, an intentional similarity given Peter Schreyer’s design influence, who previously led Audi's resurgence. The vehicle showcased a fastback silhouette with a long ovoid rear window, polished black trim around thick D-pillars, and unique LED taillights that enhanced its width and modernity. Despite fake vents and exhaust tips, the K5's proportions contributed to a sporty appearance, further emphasized by its lower and longer stance compared to the Optima.

The interior of the K5 exuded a sporty and high-quality aura, with its dash layout creating a clear division between driver and passenger spaces. Our GT-Line model featured vibrant red seats with black accents, a flat-bottom steering wheel, and an 8-inch touchscreen. Polished black trim and quality materials throughout the cabin elevated its feel, with the seats' vinyl providing a leather-like experience and hard plastics boasting a refined finish. Intricate details, from the instrument panel design to smaller elements on the door armrests, underscored Kia’s commitment to sportiness and quality that surpassed many American counterparts.

Contrastingly, the 2021 Mercedes-Benz S-Class maintained its classic yet subtly enhanced aesthetic, characterized by its wind tunnel-optimized design with a drag coefficient of 0.22, making it more aerodynamically efficient than a Toyota Prius. Though the new model echoed its predecessor's styling, it was marginally larger in every dimension, enhancing its road presence. The traditional Mercedes grille and hood ornament lent a touch of grandeur, complemented by standard 19-inch wheels, with 20- and 21-inch options available, giving the car a commanding stance.

The S-Class interior felt decisively user-centric, built around the prominent infotainment touchscreen and digital cluster that dominated the dashboard. In a move towards minimalism, Mercedes eliminated redundant controls, creating a spacious and modern cabin environment. The lighting system, vastly improved with 250 LED elements and 64 color options, further elevated the ambiance, working in harmony with driver-assist features. Material quality was top-tier, with Nappa leather, open-pore wood, and aluminum inlays enhancing the luxurious feel, although the extensive use of piano-black trim was a slight misstep, prone to smudges and reflections.

Performance in the 2021 Kia K5’s GT-Line did not fully match its aggressive styling. With a 1.6-liter turbo-four engine producing 180 horsepower and 195 lb-ft of torque, the K5 provided satisfactory acceleration, especially in traffic, aided by a responsive though sometimes rough eight-speed automatic transmission. Sport mode improved the engine's responsiveness at higher speeds. Despite good brakes and communicative steering, the GT-Line's softer suspension damping and all-season tires limited its cornering performance. Fuel economy was a strong point, with FWD models achieving an impressive 27 mpg city, 37 mpg highway, and 31 mpg combined. AWD models had slightly lower estimates. The K5 averaged nearly 36 mpg over long highway trips, an exceptional figure.

For those seeking more power, the K5's GT trim featured a 2.5-liter turbocharged four-cylinder engine with 290 horsepower and 311 lb-ft of torque, although this model was FWD-only, possibly due to supply constraints or strategic pricing. The base engine’s performance, combined with family-sedan comfort, reflected its balanced yet unenthusiastic drive experience, failing to meet the sporty expectations set by its design.

In the 2021 Mercedes-Benz S-Class, the epitome of luxury performance, the S500 4Matic featured a 3.0-liter turbocharged inline-six engine with 429 horsepower and 384 lb-ft of torque. The more powerful S580 4Matic packed a 4.0-liter twin-turbo V8, delivering 496 horsepower and 516 lb-ft of torque. Both engines integrated EQ Boost, a mild-hybrid system adding electric assist for short bursts, improving start-stop functionality and efficiency.

Mercedes claimed 0-60 mph times of 4.8 seconds for the S500 and 4.4 seconds for the S580, with electronically limited top speeds of 130 mph. While not the fastest in its class, the S-Class's times were impressive for a large sedan. Both models featured a nine-speed automatic transmission and standard air suspension, with an advanced E-Active Body Control system available. Rear-wheel steering, debuting on the S-Class, enhanced maneuverability by reducing the turning circle at low speeds.

The S580 offered a combination of speed and comfort, with precise steering and adaptive driving modes that balanced performance and ride quality effectively. Despite some wind noise, the S-Class retained composure on twisty roads, making it an excellent, if not the most thrilling, driver’s car.

The 2021 Kia K5 delivered practicality in a stylish package, accommodating two adults comfortably in the rear despite its fastback shape. Sculpted roof portions and seatbacks provided ample headroom and legroom for taller passengers. However, the absence of rear air vents was a notable omission. Front seats were firm and supportive, ideal for long drives, and the dashboard's hard buttons for climate control and audio ensured ease of use.

A standout feature was the intelligent placement of the wireless charging pad, securely positioned within easy reach. The infotainment system provided intuitive operation, and a 10-inch display with touch-sensitive buttons was optional. Trunk capacity was 16 cubic feet, offering sufficient storage space for various needs, with the added flexibility of folding rear seats.

The 2021 Mercedes-Benz S-Class excelled in spaciousness and luxury. Front seats boasted 19 motors for comprehensive adjustments, including heating, ventilation, and massage functions, creating an exceptionally comfortable environment. Despite rear seats' optional power adjustments reducing cargo space, the S-Class provided a maximum of 12.9 cubic feet, slightly larger than its predecessor but still smaller than typical in the luxury sedan segment.

Interior space was generous, with more headroom and shoulder room than competitors, although front legroom was less than ideal. The center console featured abundant storage, including a wireless phone charger and cupholders, while rear-seat passengers enjoyed their own climate controls and cupholders. An optional Executive Line package enhanced rear-seat luxury with additional climate control zones and reclining seats.

The 2021 Kia K5 offered cutting-edge technological convenience with standard wireless Apple CarPlay and Android Auto, simplifying smartphone integration without the need for cables. However, occasional issues with Apple CarPlay restarting when out of phone range occurred. The base LX trim included features like LED headlights, auto high beams, and dual-zone climate control, although it missed out on folding rear seats and push-button start.

The GT-Line trim enhanced the technology package with larger wheels, fog lights, power driver's seat, and auto up/down windows. Adding the Premium package brought additional features like a panoramic sunroof, adaptive cruise control, and more advanced LED headlights. Higher trim levels introduced heated and ventilated seats, improved infotainment systems, a Bose stereo, and remote services through Kia’s UVO link.

Mercedes-Benz’s technological prowess shone in the 2021 S-Class with its 12.3-inch digital instrument cluster and 12.8-inch OLED central touchscreen. Wireless Apple CarPlay and Android Auto, combined with six USB ports and an available 30-speaker Burmester audio system, provided an immersive experience. The updated MBUX system increased computing power by 50%, with many functions now accessible through the touchscreen or voice controls.

The S-Class also featured a pioneering augmented-reality HUD, projecting navigation directions directly onto the windshield. Rear-seat passengers benefited from additional touchscreens, enabling them to send directions to the front display. Biometric and facial recognition options elevated the user experience, while ambient lighting responded to various functions for enhanced safety and convenience. Some features, like steering-wheel touchpads, required familiarization, and certain lighting elements felt more gimmick than necessary.

The 2021 Kia K5 was too new for ratings from the NHTSA or IIHS, but its robust chassis and numerous standard safety features suggested high scores. Standard features included multiple airbags, forward emergency braking, lane-keep assist, and a driver attention monitor. Blind-spot monitoring and Safe Exit Assist were standard on all trims except the base. Advanced features like cyclist detection and Junction Turning were available on higher trims, further enhancing safety.

Similarly, the 2021 Mercedes-Benz S-Class had not been rated by major safety organizations, typical for high-end, low-volume models. Nonetheless, the S-Class was packed with advanced safety features, including a rear-passenger airbag. Standard driver-assist technologies encompassed adaptive cruise control, automated lane centering, and automatic emergency braking. Mercedes improved existing features, like lane-keep assist and traffic-sign recognition, and added capacitive steering wheel sensors for enhanced driver monitoring.