Compare the2023 Mercedes C-Class CoupeVS 2023 Porsche 718 Cayman

The C-Class Coupe’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The 718 Cayman doesn’t offer pre-crash pretensioners.

The C-Class Coupe has standard whiplash protection, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the whiplash protection system moves the headrests forward to prevent neck and spine injuries. The 718 Cayman doesn’t offer a whiplash protection system.

The C-Class Coupe offers all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The 718 Cayman doesn’t offer all-wheel drive.

The C-Class Coupe’s optional 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. The 718 Cayman doesn’t offer a lane departure warning system.

The C-Class Coupe offers an optional Surround View System to allow the driver to see objects all around the vehicle on a screen. The 718 Cayman only offers a rear monitor and front and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the sides.

The C-Class Coupe 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 718 Cayman’s blind spot costs extra.

To help make backing out of a parking space safer, the C-Class Coupe’s optional rear cross-path warning system uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The 718 Cayman doesn’t offer a cross-path warning system.

The C-Class Coupe’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 718 Cayman doesn’t offer a driver alert monitor.

Both the C-Class Coupe and the 718 Cayman 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, daytime running lights and rearview cameras.

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 C-Class Coupe’s warranty.

The 718 Cayman’s redline is at 7500 to 9000 RPM, which causes more engine wear, and a greater chance of a catastrophic engine failure. The C-Class Coupe has a 6500 RPM redline.

To reliably power the ignition and other systems and to recharge the battery, the C-Class Coupe has a standard 150-amp alternator. The 718 Cayman’s 120-amp alternator isn’t as powerful.

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.

On the EPA test cycle the C-Class Coupe gets better mileage than the 718 Cayman:

The C-Class Coupe has 3.2 gallons more fuel capacity than the 718 Cayman’s standard fuel tank (17.4 vs. 14.2 gallons), for longer range between fill-ups.

In its Green Vehicle Guide, the U.S. Environmental Protection Agency (EPA) rates the Mercedes C-Class Coupe higher (6 out of 10) than the Porsche 718 Cayman (1 to 5). This means the C-Class Coupe produces up to 45.9 pounds less smog-producing pollutants than the 718 Cayman every 15,000 miles.

The Mercedes C-Class Coupe comes standard with an automatic transmission, for driver comfort, especially in the city. Automatic costs extra on the 718 Cayman.

A nine-speed automatic is standard on the Mercedes C-Class Coupe, for better acceleration and lower engine speed on the highway. Only a seven-speed automatic is available for the 718 Cayman.

All wheel drive, available in the C-Class Coupe, provides the best traction for acceleration in wet, dry, and icy conditions. In corners, all wheel drive allows both outside wheels to provide power, balancing the car. This allows for better handling. The Porsche 718 Cayman is not available with all wheel drive.

The C-Class Coupe’s standard 245/40R18 rear tires provide better handling because they have a lower 40 series profile (height to width ratio) that provides a stiffer sidewall than the 718 Cayman’s standard 45 series tires.

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires standard on the C-Class Coupe can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The 718 Cayman doesn’t offer run-flat tires.

The C-Class Coupe 300 has a standard space-saver spare tire so you can replace a flat tire and drive to have the flat repaired or replaced. A spare tire isn’t available on the 718 Cayman; it requires you to depend on roadside assistance and your vehicle will have to be towed.

The C-Class Coupe’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 718 Cayman doesn’t offer drift compensation steering.

For a smoother ride and more stable handling, the C-Class Coupe’s wheelbase is 14.4 inches longer than on the 718 Cayman (111.8 inches vs. 97.4 inches).

For better handling and stability, the track (width between the wheels) on the C-Class Coupe is 1.6 inches wider in the front and .6 inches wider in the rear than the average track on the 718 Cayman.

For better maneuverability, the C 300’s turning circle is .7 feet tighter than the 718 Cayman GT4’s (36.8 feet vs. 37.5 feet).

The C-Class Coupe has standard seating for 4 passengers; the 718 Cayman can only carry 2.

The C-Class Coupe has 31.3 cubic feet more passenger volume than the 718 Cayman (79.3 vs. 48).

A low lift-over trunk design makes loading and unloading the C-Class Coupe easier. The C-Class Coupe’s trunk lift-over height is 25.3 inches, while the 718 Cayman’s liftover is 32.7 inches.

With its coupe body style, valet key, locking rear seatbacks and remote trunk release lockout, the C-Class offers cargo security. The 718 Cayman’s hatchback body style and non-lockable remote release defeat cargo security.

To make loading and unloading groceries and cargo easier, especially for short adults, the C-Class Coupe has a standard power trunk, which opens and closes automatically by pressing a button or just by kicking your foot under the back bumper, completely leaving your hands free. The 718 Cayman doesn’t offer a power trunk, so its trunk has to be closed manually.

Standard Trailer Stabilization Program on the C-Class Coupe uses the Electronic Stability Program sensors to detect trailer sway, then uses individual brakes to counteract any swaying and help keep the tow vehicle and trailer steady. The 718 Cayman doesn’t offer electronic trailer sway control.

The C-Class Coupe 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 718 Cayman doesn’t offer a remote starting system.

Unlike the driver-only memory system optional at extra cost in the 718 Cayman, the C-Class Coupe offers an optional 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 C-Class Coupe’s standard easy entry system raises the steering wheel and glides the driver’s seat back, making it easier for the driver to get in and out. An easy entry system costs extra on the 718 Cayman.

The C-Class Coupe offers an optional heads-up display that projects speed 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 718 Cayman doesn’t offer a heads-up display.

If the windows are left open on the C-Class Coupe 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 718 Cayman can only operate the windows from inside the vehicle, with the ignition on.

The C-Class Coupe’s power window, power lock, power mirror and cruise control switches are lit from behind, making them plainly visible and easier to operate at night. The 718 Cayman’s cruise control switches are unlit, making them difficult to find at night and operate safely.

The C-Class Coupe’s LED headlights produce a white, bright light using less electricity than the 718 Cayman’s standard xenon high intensity discharge (HID) headlights. HID headlights can be slow to reach full brightness or power cycle, causing issues when flashing them to signal other vehicles; LED headlights light instantly. LED lights also last about three to four times as long.

To shield the driver and front passenger’s vision over a larger portion of the windshield and side windows, the C-Class Coupe has standard extendable sun visors. The 718 Cayman doesn’t offer extendable visors.

To quickly and conveniently keep personal devices charged without cables tangling and wearing out, the Mercedes C-Class offers an optional wireless phone charging system (Qi) in the center console. The 718 Cayman doesn’t offer wireless personal charging.

The C-Class Coupe’s optional Active Parking Assist can parallel park or back into a parking spot by itself, stopping and changing direction automatically. The 718 Cayman doesn’t offer an automated parking system.

The Mercedes C-Class comes in coupe, convertible and sedan bodystyles; the Porsche 718 isn’t available as a sedan.

The Mercedes C-Class outsold the Porsche 718 by almost 11 to one during 2022.