Compare the2022 BMW 4 Series ConvertibleVS 2021 Mercedes C-Class Cabriolet

The 4 Series Convertible’s standard pretensioning seatbelts also sense rear collisions and remove slack from the seatbelts to help protect the occupants from whiplash and other injuries. The C-Class Cabriolet doesn’t offer a whiplash protection system.

The 4 Series Convertible 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.

Over 200 people are killed each year when backed over by motor vehicles. The 4 Series Convertible offers optional Active Park Distance Control that uses rear sensors to monitor and automatically apply the brakes to prevent a rear collision. The C-Class Cabriolet doesn’t offer backup collision prevention brakes.

The 4 Series Convertible’s 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.

To help make backing out of a parking space safer, the 4 Series Convertible has a standard cross-path warning system, which uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. Cross-path warning costs extra on the C-Class Cabriolet.

Both the 4 Series Convertible and the C-Class Cabriolet have standard driver and passenger frontal airbags, front and rear side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front and rear seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, blind spot warning systems, rearview cameras, driver alert monitors and available all wheel drive.

The 4 Series Convertible’s corrosion warranty is 7 years longer than the C-Class Cabriolet’s (12 vs. 5 years).

BMW pays for scheduled maintenance on the 4 Series Convertible 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.

J.D. Power and Associates’ 2020 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 18th in initial quality. With 26 more problems per 100 vehicles, Mercedes is ranked 30th.

J.D. Power and Associates’ 2021 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 10th in reliability, above the industry average. With 14 more problems per 100 vehicles, Mercedes is ranked 15th.

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 430i Convertible’s standard 2.0 turbo 4-cylinder produces 21 lbs.-ft. more torque (294 vs. 273) than the C-Class Cabriolet’s 2.0 turbo 4-cylinder. The M440i Convertible’s standard 3.0 turbo 6-cylinder hybrid produces 127 more horsepower (382 vs. 255) and 95 lbs.-ft. more torque (368 vs. 273) than the C-Class Cabriolet’s 2.0 turbo 4-cylinder.

On the EPA test cycle the 4 Series Convertible gets better mileage than the C-Class Cabriolet:

Regenerative brakes improve the 4 Series Convertible’s fuel efficiency by converting inertia back into energy instead of wasting it. The C-Class Cabriolet doesn’t offer a regenerative braking system.

Both the 4 Series Convertible and the C-Class Cabriolet have a standard automatic start/stop engine feature to stop unnecessary fuel waste and pollution at stop lights and heavy traffic. All 4 Series Convertibles have a standard disable switch for the system, so a driver can keep the engine from shutting off when the vehicle stops temporarily.

The U.S. Environmental Protection Agency (EPA) certifies the BMW 4 Series Convertible as a “Super Ultra Low Emissions Vehicle” (SULEV). The Mercedes C-Class Cabriolet is only certified to “Ultra Low Emissions Vehicle” (ULEV) standards.

The 4 Series Convertible’s 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 4 Series Convertible M440i’s brake rotors are larger than those on the C-Class Cabriolet:

The 4 Series Convertible offers an available 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 4 Series Convertible is .6 inches wider in the front and 2.6 inches wider in the rear than on the C-Class Cabriolet.

The 4 Series Convertible has 2.7 cubic feet more passenger volume than the C-Class Cabriolet (84 vs. 81.3).

The 4 Series Convertible has 1.8 inches more front headroom, .3 inches more front shoulder room, .5 inches more rear headroom and .5 inches more rear legroom than the C-Class Cabriolet.

The 4 Series Convertible has a much larger trunk with its top down than the C-Class Cabriolet with its top down (10.6 vs. 7 cubic feet). The 4 Series Convertible has a much larger trunk with its top up than the C-Class Cabriolet with its top up (13.6 vs. 8.8 cubic feet).

To make loading and unloading groceries and cargo easier, especially for short adults, the 4 Series Convertible offers an optional power trunk, which opens and closes automatically by pressing a button, or optionally by just waving your foot, completely leaving your hands free. The C-Class Cabriolet doesn’t offer a power trunk.