Compare the2023 Audi A3VS 2022 Mercedes C-Class Sedan

Both the A3 and C-Class Sedan have child safety locks to prevent children from opening the rear doors. The A3 has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The C-Class Sedan’s child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.

The Audi A3 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 C-Class Sedan doesn’t offer a front passenger side knee airbag.

The A3’s 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 C-Class Sedan doesn’t offer a lane departure warning system.

Both the A3 and the C-Class Sedan have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, rearview cameras, available all wheel drive, blind spot warning systems, rear parking sensors and rear cross-path warning.

For its top level performance in IIHS driver and passenger-side small overlap frontal, moderate overlap frontal, side impact, roof strength and head restraint tests, its standard vehicle-to-vehicle front crash prevention system, its standard vehicle-to-pedestrian front crash prevention system, and its standard headlight’s “Good” rating, the Insurance Institute for Highway Safety grants the A3 its highest rating: “Top Safety Pick Plus” for 2022, a rating granted to only 101 vehicles tested by the IIHS. The C-Class Sedan has not been tested, yet.

The A3’s corrosion warranty is 7 years longer than the C-Class Sedan’s (12 vs. 5 years).

The Audi A3’s engine uses a cast iron block for durability, while the C-Class Sedan’s engine uses an aluminum block. Aluminum engine blocks are much more prone to warp and crack at high temperatures than cast iron.

From surveys of all its subscribers, Consumer Reports’ January 2021 Auto Issue reports that Audi vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks Audi 6 places higher in reliability than Mercedes.

On the EPA test cycle the A3 gets better mileage than the C-Class Sedan:

To lower fuel costs and make buying fuel easier, the Audi A3 uses regular unleaded gasoline (premium recommended for maximum performance). The C-Class Sedan requires premium, which can cost 20 to 55 cents more per gallon.

The A3 offers a standard sequential manual gearbox (SMG). With no clutch pedal to worry about and a fully automatic mode, an SMG is much more efficient than a conventional automatic but just as easy to drive. The C-Class Sedan doesn’t offer an SMG or a conventional manual transmission.

The A3 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 C-Class Sedan; it requires you to depend on its run-flat tires, which limits mileage and speed before they are repaired. If a run-flat is damaged beyond repair by a road hazard your vehicle will have to be towed. Some tire options on the C-Class Sedan don’t have a run-flat feature, either.

The A3 offers an optional 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 Sedan’s suspension doesn’t offer adjustable shock absorbers.

The Audi A3 may be more efficient, handle and accelerate better because it weighs about 350 to 500 pounds less than the Mercedes C-Class Sedan.

The A3 is 10.1 inches shorter than the C-Class Sedan, making the A3 easier to handle, maneuver and park in tight spaces.

J.D. Power and Associates surveys of service recipients show that Audi service is better than Mercedes. J.D. Power ranks Audi 8th in service department satisfaction (above the industry average). With a 16% lower rating, Mercedes is ranked 18th.

In poor weather, headlights can lose their effectiveness as grime builds up on their lenses. This can reduce visibility without the driver realizing. The A3 Prestige has standard headlight washers to keep headlight output high. The C-Class Sedan doesn’t offer headlight washers.

Consumer Reports® recommends the Audi A3, based on reliability, safety and performance.