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

Both the 8 Series and the 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 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 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 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 840i’s standard 3.0 turbo 6-cylinder produces 80 more horsepower (335 vs. 255) and 95 lbs.-ft. more torque (368 vs. 273) than the C-Class Cabriolet’s 2.0 turbo 4-cylinder. The M850i’s standard 4.4 turbo V8 produces 268 more horsepower (523 vs. 255) and 280 lbs.-ft. more torque (553 vs. 273) than the C-Class Cabriolet’s 2.0 turbo 4-cylinder.

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

The 8 Series’ launch control uses engine electronics to hold engine RPM’s precisely in order to provide the most stable and rapid acceleration possible, using all of the available traction. The C-Class Cabriolet doesn’t offer launch control.

For better stopping power the 8 Series’ brake rotors are larger than those on the C-Class Cabriolet:

For better traction, the 8 Series has larger tires than the 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 C-Class Cabriolet’s standard 45 series front and 40 series rear tires. The 8 Series’ optional 245/35R20 front and 275/30R20 rear tires have a lower 35 series front and 30 series rear profile than the AMG C 43 Cabriolet’s optional 40 series front and 35 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 C-Class Cabriolet. The 8 Series’ optional 20-inch wheels are larger than the 19-inch wheels optional on the AMG C 43 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 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 C-Class Cabriolet.

The 8 Series has a standard driver-adjustable suspension system. It allows the driver to choose between an extra-supple ride, reducing fatigue on long trips, or a sport setting, which allows maximum control for tricky roads. The C-Class Cabriolet’s suspension doesn’t offer adjustable shock absorbers.

For better handling and stability, the track (width between the wheels) on the 8 Series is 2.4 inches wider in the front and 4.5 inches wider in the rear than on the C-Class Cabriolet.

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

The 8 Series has a standard heated steering wheel to take the chill out of steering on extremely cold winter days before the car heater warms up. A heated steering wheel costs extra on the C-Class Cabriolet.