Compare the2025 BMW 3 Series SedanVS 2024 Mercedes C-Class Sedan

In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the 3 Series Sedan are reminded to check the back seat if they opened the rear door before starting out. The C-Class Sedan doesn’t offer a back seat reminder.

The BMW 3 Series Sedan 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 3 Series Sedan has standard Active Head Restraints, which use a specially designed headrest to protect the driver and front passenger from whiplash. During a rear-end collision, the Active Head Restraints system moves the headrests forward to prevent neck and spine injuries. The C-Class Sedan doesn’t offer a whiplash protection system.

The 3 Series Sedan’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 C-Class Sedan doesn’t offer a lane departure warning system.

Both the 3 Series Sedan 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, 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, driver alert monitors, available all wheel drive, blind spot warning systems, around view monitors and rear cross-path warning.

The 3 Series Sedan’s corrosion warranty is 7 years longer than the C-Class Sedan’s (12 vs. 5 years).

BMW pays for scheduled maintenance on the 3 Series Sedan for 3 years and 36,000 miles. BMW will pay for oil changes, tire rotations, air filter replacements, cabin filter replacement, brake fluid replacement, inspections, and any other required maintenance. Mercedes doesn’t pay scheduled maintenance for the C-Class Sedan.

A reliable vehicle saves its owner time, money and trouble. Nobody wants to be stranded or have to be without a vehicle while it’s being repaired. Consumer Reports rates the 3 Series Sedan’s reliability 40 points higher than the C-Class Sedan.

J.D. Power and Associates rated the 3 Series Sedan third among compact premium cars in their 2024 Initial Quality Study. The C-Class Sedan isn’t in the top three in its category.

J.D. Power and Associates’ 2024 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 With 28 fewer problems per 100 vehicles in the first three years of ownership, J.D. Power ranks BMW higher than Mercedes.

From surveys of all its subscribers, Consumer Reports’ January 2024 Auto Issue reports that BMW vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks BMW 20 places higher in reliability than Mercedes.

The M340i’s standard 3.0 turbo 6-cylinder hybrid produces 131 more horsepower (386 vs. 255) and 103 lbs.-ft. more torque (398 vs. 295) than the C-Class Sedan’s 2.0 turbo 4-cylinder hybrid.

As tested in Consumer Reports the 330i 2.0 turbo 4-cylinder is faster than the Mercedes C-Class Sedan:

On the EPA test cycle the 3 Series Sedan gets better mileage than the C-Class Sedan:

To lower fuel costs and make buying fuel easier, the BMW 3 Series Sedan uses regular unleaded gasoline (premium recommended for maximum performance). The C-Class Sedan requires premium, which can cost on average about 84.9 cents more per gallon.

The 3 Series Sedan’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 Sedan doesn’t offer launch control.

For better stopping power the M340i’s brake rotors are larger than those on the C-Class Sedan:

The 3 Series Sedan stops much shorter than the C-Class Sedan:

The 3 Series Sedan offers an optional 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 3 Series Sedan 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 front grille of the 3 Series 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 C-Class Sedan doesn’t offer active grille shutters.

The 3 Series Sedan has .3 inches more front legroom and .1 inches more rear headroom than the C-Class Sedan.

The 3 Series Sedan has a much larger trunk than the C-Class Sedan (16.9 vs. 12.6 cubic feet).

Both the 3 Series Sedan and the C-Class Sedan have standard heated front seats. The 3 Series Sedan also offers optional heated rear seats to keep those passengers extremely comfortable in the winter. Heated rear seats aren’t available in the C-Class Sedan.

Consumer Reports® recommends the BMW 3 Series Sedan, based on reliability, safety and performance. The Mercedes C-Class Sedan isn't recommended.

J.D. Power and Associates rated the 3 Series Sedan third among compact premium cars in owner reported satisfaction. This includes how well the vehicle performs and satisfies its owner’s expectations. The C-Class Sedan isn’t in the top three.

The BMW 3 Series outsold the Mercedes C-Class by 1299 units during 2023.