Compare the2023 BMW 3 Series SedanVS 2023 Mercedes CLA

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 CLA 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 M340i offers an optional Active Park Distance Control that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The CLA doesn’t offer automatic braking for stationary objects directly to the rear.

Both the 3 Series Sedan and the CLA 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, crash mitigating brakes, daytime running lights, rearview cameras, driver alert monitors, available all wheel drive, lane departure warning systems, blind spot warning systems, around view monitors and rear cross-path warning.

For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, and its standard front crash prevention system, the Insurance Institute for Highway Safety grants the 3 Series Sedan the rating of “Top Safety Pick” for 2017, a rating granted to only 235 vehicles tested by the IIHS. The CLA has not been tested, yet.

The 3 Series Sedan’s corrosion warranty is 7 years longer than the CLA’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 CLA.

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 50 points higher than the CLA.

J.D. Power and Associates’ 2022 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 above average in initial quality. With 24 more problems per 100 vehicles, Mercedes is rated below average.

J.D. Power and Associates’ 2022 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 above average in long-term dependability. With 5 more problems per 100 vehicles in the first three years of ownership, Mercedes is rated below average.

From surveys of all its subscribers, Consumer Reports’ January 2023 Auto Issue reports that BMW vehicles are more reliable than Mercedes vehicles. Consumer Reports ranks BMW third in overall reliability. Mercedes is ranked 24th.

The 330i’s standard 2.0 turbo 4-cylinder produces 34 more horsepower (255 vs. 221) and 36 lbs.-ft. more torque (294 vs. 258) than the CLA’s 2.0 turbo 4-cylinder. The M340i’s standard 3.0 turbo 6-cylinder hybrid produces 161 more horsepower (382 vs. 221) and 110 lbs.-ft. more torque (368 vs. 258) than the CLA’s 2.0 turbo 4-cylinder.

As tested in Motor Trend the BMW 3 Series Sedan is faster than the Mercedes CLA:

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

The 3 Series Sedan has 2.1 gallons more fuel capacity than the CLA (15.6 vs. 13.5 gallons), for longer range between fill-ups.

An eight-speed automatic is standard on the BMW 3 Series Sedan, for better acceleration and lower engine speed on the highway. Only a seven-speed automatic is available for the CLA.

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 CLA doesn’t offer launch control.

For better stopping power the M340i’s brake rotors are larger than those on the CLA:

The 3 Series Sedan’s standard front and rear disc brakes are vented to help dissipate heat for shorter stops with less fading. The rear discs on the CLA are solid, not vented.

The 3 Series Sedan stops much shorter than the CLA:

The 3 Series Sedan’s optional 255/35R19 rear tires provide better handling because they have a lower 35 series profile (height to width ratio) that provides a stiffer sidewall than the CLA’s optional 40 series tires.

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 CLA; 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 CLA don’t have a run-flat feature, either.

For a smoother ride and more stable handling, the 3 Series Sedan’s wheelbase is 4.8 inches longer than on the CLA (112.2 inches vs. 107.4 inches).

The 3 Series Sedan’s front to rear weight distribution is more even (51.3% to 48.7%) than the CLA’s (60% to 40%). This gives the 3 Series Sedan more stable handling and braking.

The 330i handles at .95 G’s, while the CLA 250 4MATIC pulls only .86 G’s of cornering force in a Motor Trend skidpad test.

The M340i executes Motor Trend’s “Figure Eight” maneuver 1.5 seconds quicker than the CLA 250 4MATIC (25 seconds @ .77 average G’s vs. 26.5 seconds @ .67 average G’s).

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 CLA doesn’t offer active grille shutters.

The 3 Series Sedan has .2 inches more front headroom, .2 inches more front legroom, .9 inches more front shoulder room, 1.9 inches more rear headroom, 1.3 inches more rear legroom and .6 inches more rear shoulder room than the CLA.

The 3 Series Sedan has a much larger trunk than the CLA (13 vs. 11.6 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 CLA’s liftover is 30.1 inches.

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

With its sedan body style, valet key, locking rear seatbacks and remote trunk release lockout, the 3 Series offers cargo security. The CLA’s non-lockable remote release defeats cargo security.

To make loading and unloading groceries and cargo easier, especially for short adults, the 3 Series Sedan offers an optional power trunk, which opens and closes automatically by pressing a button, or optionally by just kicking your foot under the back bumper, completely leaving your hands free. The CLA doesn’t offer a power trunk, so its trunk has to be closed manually.

The engine in the 3 Series Sedan is mounted longitudinally (North-South), instead of sideways, as in the CLA. This makes it easier to service and maintain, because the accessory belts are in front.

J.D. Power and Associates surveys of service recipients show that BMW service is better than Mercedes. J.D. Power ranks BMW 7th in service department satisfaction (above the industry average). With a 17% lower rating, Mercedes is ranked 18th.

Consumer Reports rated the 3 Series Sedan’s headlight performance “Fair,” a higher rating than the CLA’s headlights, which were rated “Poor.”

To shield the driver and front passenger’s vision over a larger portion of the windshield and side windows, the 3 Series Sedan has standard extendable sun visors. The CLA doesn’t offer extendable visors.

Both the 3 Series Sedan and the CLA offer optional 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 CLA.

The 3 Series Sedan will cost the buyer less in the long run because of its superior resale value. The IntelliChoice estimates that the 3 Series Sedan will retain 44.47% to 45.8% of its original price after five years, while the CLA only retains 41.76% to 41.79%.

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

The BMW 3 Series outsold the Mercedes CLA by over three to one during 2022.