Compare the2023 Mercedes AMG C-Class CabrioletVS 2023 Porsche 911

For enhanced safety, the front and rear seat shoulder belts of the Mercedes AMG C-Class Cabriolet have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The Porsche 911 doesn’t offer pretensioners for its rear seat belts.

The AMG C-Class Cabriolet’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The 911 doesn’t offer pre-crash pretensioners.

The Mercedes AMG C-Class Cabriolet has standard driver and front passenger side knee airbags mounted low on the dashboard. These airbags helps prevent the driver and front passenger from sliding under their seatbelts or the main frontal airbags; this keeps them better positioned during a collision for maximum protection. Knee airbags also help keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The 911 doesn’t offer knee airbags.

The AMG C-Class Cabriolet has standard front and rear seat side-impact airbags and head airbags, which act as a forgiving barrier between the passengers and the door. Combined with high-strength steel door beams this system increases protection from broadside collisions. The 911 doesn't offer rear-seat side-impact airbags, only ones for front seat occupants.

To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the AMG C-Class Cabriolet. But it costs extra on the 911.

The AMG C-Class Cabriolet has a standard blind spot warning system which uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them. A system to reveal vehicles in the 911’s blind spot costs extra.

The AMG C-Class Cabriolet’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The 911 doesn’t offer a driver alert monitor.

Both the AMG C-Class Cabriolet and the 911 have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, rearview cameras, available lane departure warning systems, around view monitors and rear cross-path warning.

The Mercedes AMG C-Class Cabriolet weighs 414 to 1078 pounds more than the Porsche 911. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.

There are almost 2 times as many Mercedes dealers as there are Porsche dealers, which makes it much easier should you ever need service under the AMG C-Class Cabriolet’s warranty.

J.D. Power and Associates’ 2022 Initial Quality Study of new car owners surveyed provide the statistics that show that Mercedes vehicles are better in initial quality than Porsche vehicles. With 11 fewer problems per 100 vehicles, JD Power ranks Mercedes higher than Porsche.

The AMG C-Class Cabriolet’s 3.0 turbo V6 produces 6 more horsepower (385 vs. 379) and 53 lbs.-ft. more torque (384 vs. 331) than the 911’s standard 3.0 turbo 6-cylinder.

On the EPA test cycle the AMG C-Class Cabriolet gets better mileage than the 911 Cabriolet:

In its Green Vehicle Guide, the U.S. Environmental Protection Agency (EPA) rates the Mercedes AMG C-Class Cabriolet higher (5 out of 10) than the Porsche 911 (3 to 5). This means the AMG C-Class Cabriolet produces up to 16.5 pounds less smog-producing pollutants than the 911 every 15,000 miles.

A nine-speed automatic is standard on the Mercedes AMG C-Class Cabriolet, for better acceleration and lower engine speed on the highway. Only an eight-speed automatic is available for the 911.

For better stopping power the AMG C-Class Cabriolet’s standard front brake rotors are larger than those on the 911:

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires standard on the AMG C-Class Cabriolet can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The 911 doesn’t offer run-flat tires.

The AMG C-Class Cabriolet’s drift compensation steering can automatically compensate for road conditions which would cause the vehicle to drift from side to side, helping the driver to keep the vehicle straight more easily. The 911 doesn’t offer drift compensation steering.

For a smoother ride and more stable handling, the AMG C-Class Cabriolet’s wheelbase is 15.3 inches longer than on the 911 (111.8 inches vs. 96.5 inches).

The AMG C-Class Cabriolet has 8.3 cubic feet more passenger volume than the 911 (81.3 vs. 73).

The AMG C-Class Cabriolet has .9 inches more front headroom, 2.2 inches more front shoulder room, 3.1 inches more rear headroom and 4.8 inches more rear legroom than the 911.

The AMG C-Class Cabriolet has a much larger trunk with its top down than the 911 Cabriolet with its top down (7 vs. 4.6 cubic feet).

With its convertible body style, locking rear seatbacks and remote trunk release lockout, the AMG C-Class offers cargo security. The 911’s non-lockable folding seat defeats cargo security.

The AMG C-Class Cabriolet has a standard remote vehicle starting system, so the vehicle can be started from inside the driver's house. This allows the driver to comfortably warm up the engine before going out to the vehicle. The climate system will also automatically heat or cool the interior. The 911 doesn’t offer a remote starting system.

Unlike the driver-only memory system optional at extra cost in the 911, the AMG C-Class Cabriolet has standard driver and passenger memory, so that when drivers switch, the memory setting adjusts the driver’s seat, steering wheel position and outside mirror angle and the front passenger seat also adjusts to the new passenger’s preset preferences.

The AMG C-Class Cabriolet’s standard easy entry system raises the steering wheel, making it easier for the driver to get in and out. An easy entry system costs extra on the 911.

The AMG C-Class Cabriolet offers an optional heads-up display that projects speed, tachometer, warning and navigation instruction readouts in front of the driver’s line of sight, allowing drivers to view information without diverting their eyes from the road. The 911 doesn’t offer a heads-up display.

The AMG C-Class Cabriolet’s standard power windows have a locking feature to keep children in the rear seat from operating them, but the driver can still raise and lower all of them with the lock engaged. Porsche does not offer a locking feature on the 911’s standard power windows.

If the windows are left open on the AMG C-Class Cabriolet the driver can close them all at the outside door handle or from a distance using the remote. On a hot day the driver can lower the windows from a distance using the keyless remote. The driver of the 911 can only operate the windows from inside the vehicle, with the ignition on.

In case of a sudden change of weather, the AMG C-Class Cabriolet has a standard remote convertible top that can be raised from a distance to protect the interior of the vehicle from damage. On a hot day the AMG C-Class Cabriolet has a standard remote opening feature, to lower the top from outside. The 911 doesn’t offer a remote top, so the driver will have to run to the car, get in, turn the ignition on and raise the top to prevent the interior from being damaged.

To shield the driver and front passenger’s vision over a larger portion of the windshield and side windows, the AMG C-Class Cabriolet has standard extendable sun visors. The 911 doesn’t offer extendable visors.

To quickly and conveniently keep personal devices charged without cables tangling and wearing out, the Mercedes AMG C-Class offers an optional wireless phone charging system (Qi) in the center console. The 911 doesn’t offer wireless personal charging.

The Mercedes AMG C-Class comes in coupe, convertible and sedan bodystyles; the Porsche 911 isn’t available as a sedan.

Insurance will cost less for the AMG C-Class Cabriolet owner. The Complete Car Cost Guide estimates that insurance for the AMG C-Class Cabriolet will cost $705 less than the 911 over a five-year period.

IntelliChoice estimates that five-year ownership costs (depreciation, financing, insurance, fuel, fees, repairs and maintenance) for the Mercedes AMG C-Class Cabriolet will be $11499 to $72109 less than for the Porsche 911.

The Mercedes C-Class outsold the Porsche 911 by almost four to one during 2022.