Compare the2022 BMW 3 Series SedanVS 2021 Mercedes C-Class Sedan

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 has a standard PostCrash iBrake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The C-Class Sedan doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.

Over 200 people are killed each year when backed over by motor vehicles. The 3 Series Sedan offers optional Active Park Distance Control that uses rear sensors to monitor and automatically apply the brakes to prevent a rear collision. The C-Class Sedan doesn’t offer backup collision prevention brakes.

The 3 Series Sedan’s standard 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. A lane departure warning system costs extra on the C-Class Sedan.

Both the 3 Series Sedan and the C-Class Sedan have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, driver alert monitors, available all wheel drive, blind spot warning systems, rear parking sensors 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, lubrication and any other required maintenance. Mercedes doesn’t pay scheduled maintenance for the C-Class Sedan.

The battery on the 3 Series Sedan is in the trunk, which protects it from hot underhood temperatures that can degrade battery life. By keeping the 3 Series Sedan’s battery 20 to 30 degrees cooler, its life is increased by years. The C-Class Sedan’s battery is in the hot engine compartment.

J.D. Power and Associates’ 2020 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than Mercedes vehicles. J.D. Power ranks BMW 18th in initial quality. With 26 more problems per 100 vehicles, Mercedes is ranked 30th.

J.D. Power and Associates’ 2021 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 vehicles. J.D. Power ranks BMW 10th in reliability, above the industry average. With 14 more problems per 100 vehicles, Mercedes is ranked 15th.

From surveys of all its subscribers, Consumer Reports’ January 2021 Auto Issue reports that BMW vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks BMW 8 places higher in reliability than Mercedes.

The 330i’s standard 2.0 turbo 4-cylinder produces 21 lbs.-ft. more torque (294 vs. 273) than the C-Class Sedan’s 2.0 turbo 4-cylinder. The M340i’s standard 3.0 turbo 6-cylinder hybrid produces 127 more horsepower (382 vs. 255) and 95 lbs.-ft. more torque (368 vs. 273) than the C-Class Sedan’s 2.0 turbo 4-cylinder.

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

Regenerative brakes improve the 3 Series Sedan’s fuel efficiency by converting inertia back into energy instead of wasting it. The C-Class Sedan doesn’t offer a regenerative braking system.

Both the 3 Series Sedan and the C-Class Sedan have a standard automatic start/stop engine feature to stop unnecessary fuel waste and pollution at stop lights and heavy traffic. All 3 Series Sedans have a standard disable switch for the system, so a driver can keep the engine from shutting off when the vehicle stops temporarily.

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 shorter than the C-Class Sedan:

The 330i’s standard tires provide better handling because they have a lower 45 series profile (height to width ratio) that provides a stiffer sidewall than the C-Class Sedan’s 50 series tires. The 3 Series Sedan’s optional 225/35R20 front and 255/30R20 rear tires have a lower 35 series front and 30 series rear profile than the C-Class Sedan’s optional 40 series front and 35 series rear tires.

For better ride, handling and brake cooling the 330i has standard 18-inch wheels. Smaller 17-inch wheels are standard on the C-Class Sedan. The 3 Series Sedan’s optional 20-inch wheels are larger than the 19-inch wheels optional on the C-Class Sedan.

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.

For better handling and stability, the average track (width between the wheels) on the 3 Series Sedan is .8 inches wider in the front and 2.1 inches wider in the rear than the average track on the C-Class Sedan.

The 330i handles at .95 G’s, while the C 300 Sedan 4MATIC pulls only .87 G’s of cornering force in a Motor Trend skidpad test.

The M340i executes Motor Trend’s “Figure Eight” maneuver 1.3 seconds quicker than the C 300 Sedan 4MATIC (25 seconds @ .77 average G’s vs. 26.3 seconds @ .7 average G’s).

The design of the BMW 3 Series Sedan amounts to more than styling. The 3 Series Sedan has an aerodynamic coefficient of drag of .26 Cd. That is significantly lower than the C-Class Sedan (.3) and many sports cars. A more efficient exterior helps keep the interior quieter and helps the 3 Series Sedan get better fuel mileage.

The 3 Series Sedan has 1.6 inches more front headroom, .3 inches more front legroom, .7 inches more front shoulder room and .5 inches more rear headroom than the C-Class Sedan.

The 3 Series Sedan has a larger trunk than the C-Class Sedan (13 vs. 12.6 cubic feet).

A low lift-over trunk design makes loading and unloading the 3 Series Sedan easier. The 3 Series Sedan’s trunk lift-over height is 26.7 inches, while the C-Class Sedan’s liftover is 28 inches.

Pulling a handle automatically lowers the 3 Series Sedan’s rear seats, to make changing between passengers and cargo easier. The C-Class Sedan doesn’t offer automatic folding seats.

Both the 3 Series Sedan and the C-Class Sedan offer available 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.

According to The Car Book by Jack Gillis, the 3 Series Sedan is less expensive to operate than the C-Class Sedan because it costs $346 less to do the manufacturer’s suggested maintenance for 50,000 miles. Typical repairs cost much less on the 3 Series Sedan than the C-Class Sedan, including $43 less for a muffler, $593 less for a fuel pump and $146 less for a power steering pump.

Consumer Reports® recommends both the BMW 3 Series Sedan and the Mercedes C-Class Sedan, based on reliability, safety and performance.