The C-Class Sedan’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 S5 Sportback doesn’t offer a driver alert monitor.
Both the C-Class Sedan and the S5 Sportback have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front and rear seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, available all wheel drive, lane departure warning systems, blind spot warning systems and around view monitors.
There are over 29 percent more Mercedes dealers than there are Audi dealers, which makes it easier should you ever need service under the C-Class Sedan’s warranty.
J.D. Power and Associates’ 2017 Initial Quality Study of new car owners surveyed provide the statistics that show that Mercedes vehicles are better in initial quality than Audi vehicles. J.D. Power ranks Mercedes 17th in initial quality. With 13 more problems per 100 vehicles, Audi is ranked 26th.
The AMG C 43 Sedan’s standard 3.0 turbo V6 produces 8 more horsepower (362 vs. 354) and 15 lbs.-ft. more torque (384 vs. 369) than the S5 Sportback’s 3.0 turbo V6.
The C-Class Sedan has 2.1 gallons more fuel capacity than the S5 Sportback (17.4 vs. 15.3 gallons), for longer range between fill-ups.
For better stopping power the AMG C 43 Sedan’s front brake rotors are larger than those on the S5 Sportback:
AMG C 43
Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires available on the C-Class Sedan can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The S5 Sportback doesn’t offer run-flat tires.
The C-Class Sedan has a standard automatic front and rear load leveling suspension to keep ride height level with a heavy load or when towing. The C-Class Sedan’s height leveling suspension allows the driver to raise ride height for better off-road clearance and then lower it again for easier entering and exiting and better on-road handling. The S5 Sportback doesn’t offer a load leveling suspension.
The C-Class Sedan’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 S5 Sportback doesn’t offer drift compensation steering.
For better maneuverability, the C-Class Sedan’s turning circle is 1.6 feet tighter than the S5 Sportback’s (36.8 feet vs. 38.4 feet).
The Mercedes C-Class Sedan may be more efficient, handle and accelerate better because it weighs about 150 to 500 pounds less than the Audi S5 Sportback.
The front grille of the C-Class Sedan uses electronically controlled shutters to close off airflow and reduce drag when less engine cooling is needed. This helps improve highway fuel economy. The S5 Sportback doesn’t offer active grille shutters.
As tested by Car and Driver while under full throttle, the interior of the AMG C 43 Sedan is quieter than the S5 Sportback Prestige (78 vs. 79 dB).
The C-Class Sedan has .4 inches more front legroom, .1 inches more rear headroom, .1 inches more rear legroom and .5 inches more rear shoulder room than the S5 Sportback.
With its sedan body style, valet key, locking rear seatbacks and remote trunk release lockout, the C-Class offers cargo security. The S5 Sportback’s hatchback body style defeats cargo security.
The C-Class Sedan 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 S5 Sportback doesn’t offer a remote starting system.
Unlike the driver-only memory system in the S5 Sportback, the C-Class Sedan 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.
If the windows are left open on the C-Class Sedan 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 also lower the windows the same way. The driver of the S5 Sportback can’t use the remote to operate the windows.
To help drivers see further while navigating curves, the C-Class Sedan offers optional adaptive headlights to illuminate around corners automatically by reading vehicle speed and steering wheel angle. The S5 Sportback doesn’t offer cornering lights.
A power rear sunshade is optional in the C-Class Sedan to help block heat and glare for the rear passengers. The S5 Sportback doesn’t offer a rear sunshade.
The C-Class Sedan’s optional Active Parking Assist can parallel park or back into a parking spot by itself, with the driver only controlling speed with the brake pedal. The S5 Sportback doesn’t offer an automated parking system.
The C-Class Sedan was chosen as one of Automobile Magazine’s “All Stars” in 2015. The S5 Sportback has never been an “All Star.”
The Mercedes C-Class outsold the Audi A5/S5/RS 5 by almost four to one during 2017.