Compare the2023 BMW 8 SeriesVS 2021 Mercedes AMG C-Class Cabriolet

The 8 Series has a standard PostCrash iBrake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The AMG C-Class Cabriolet doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.

The 8 Series’ standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the AMG C-Class Cabriolet.

Both the 8 Series and the AMG C-Class Cabriolet have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, driver alert monitors, available blind spot warning systems, rear parking sensors and rear cross-path warning.

The 8 Series’ corrosion warranty is 7 years longer than the AMG C-Class Cabriolet’s (12 vs. 5 years).

BMW pays for scheduled maintenance on the 8 Series for 3 years and 36,000 miles. BMW will pay for oil changes, lubrication and any other required maintenance. Mercedes doesn’t pay scheduled maintenance for the AMG C-Class Cabriolet.

A reliable vehicle saves its owner time, money and trouble. Nobody wants to be stranded or have to be without a vehicle while it’s being repaired. Consumer Reports rates the 8 Series’ reliability 20 points higher than the AMG C-Class Cabriolet.

J.D. Power and Associates’ 2022 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than Mercedes vehicles. J.D. Power ranks BMW above average in initial quality. With 24 more problems per 100 vehicles, Mercedes is rated below average.

J.D. Power and Associates’ 2022 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that BMW vehicles are more reliable than Mercedes vehicles. J.D. Power ranks BMW above average in long-term dependability. With 5 more problems per 100 vehicles in the first three years of ownership, Mercedes is rated below average.

From surveys of all its subscribers, Consumer Reports’ January 2021 Auto Issue reports that BMW vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks BMW 8 places higher in reliability than Mercedes.

The 8 Series has more powerful engines than the AMG C-Class Cabriolet:

As tested in Car and Driver the M850i 4.4 turbo V8 is faster than the AMG C 63 S Cabriolet 4.0 turbo V8:

On the EPA test cycle the 8 Series Convertible gets better mileage than the AMG C-Class Cabriolet:

Regenerative brakes improve the 8 Series’ fuel efficiency by converting inertia back into energy instead of wasting it. The AMG C-Class Cabriolet doesn’t offer a regenerative braking system.

For better traction, the 8 Series has larger tires than the AMG C-Class Cabriolet (F:245/35R20 & R:275/30R20 vs. F:225/45R18 & R:245/40R18).

The 8 Series’ standard 245/40R19 front and 275/35R19 rear tires provide better handling because they have a lower 40 series front and 35 series rear profile (height to width ratio) that provides a stiffer sidewall than the AMG C 43 Cabriolet’s standard 45 series front and 40 series rear tires.

For better ride, handling and brake cooling the 8 Series has standard 19-inch wheels. Smaller 18-inch wheels are standard on the AMG C 63 Cabriolet. The 8 Series’ optional 20-inch wheels are larger than the 19-inch front wheels and 20-inch rear wheels optional on the AMG C 63 S Cabriolet.

The 8 Series M850i has active sway bars, which help keep it flat and controlled during cornering, but disconnect at lower speeds to smooth the ride and offer greater off-road suspension articulation. This helps keep the tires glued to the road on-road and off. The AMG C-Class Cabriolet doesn’t offer an active sway bar system.

The M850i offers an available active suspension system, which counteracts cornering forces actively, limiting body roll and improving handling and stability. Mercedes doesn’t offer an active suspension on the AMG C-Class Cabriolet.

For better handling and stability, the track (width between the wheels) on the 8 Series is .3 inches wider in the front and 2.6 inches wider in the rear than the average track on the AMG C-Class Cabriolet.

The BMW 8 Series may be more efficient, handle and accelerate better because it weighs up to about 350 pounds less than the Mercedes AMG C-Class Cabriolet.

The front grille of the 8 Series uses electronically controlled shutters to close off airflow and reduce drag when less engine cooling is needed. This helps improve highway fuel economy. The AMG C-Class Cabriolet doesn’t offer active grille shutters.

The 8 Series Convertible has a much larger trunk with its top down than the AMG C-Class Cabriolet with its top down (12.4 vs. 7 cubic feet). The 8 Series Convertible has a much larger trunk than the AMG C-Class Cabriolet with its top up (12.4 vs. 8.8 cubic feet).

Pulling a handle automatically lowers the 8 Series’ rear seats, to make changing between passengers and cargo easier. The AMG C-Class Cabriolet doesn’t offer automatic folding seats.

To make loading and unloading groceries and cargo easier when your hands are full, the 8 Series’ power trunk can be opened or closed just by kicking your foot under the back bumper, leaving your hands completely free. The AMG C-Class Cabriolet doesn’t offer a power or hands-free opening trunk.

J.D. Power and Associates surveys of service recipients show that BMW service is better than Mercedes. J.D. Power ranks BMW 7th in service department satisfaction (above the industry average). With a 17% lower rating, Mercedes is ranked 18th.

On extremely cold winter days, the 8 Series’ standard heated steering wheel provides comfort, allowing the driver to steer safely and comfortably before the car heater warms up. The AMG C-Class Cabriolet doesn’t offer a heated steering wheel.