Compare the2025 BMW 3 Series SedanVS 2024 Audi S3

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 S3 doesn’t offer a back seat reminder.

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 S3 doesn’t offer a whiplash protection system.

Over 200 people are killed each year when backed over by motor vehicles. The 3 Series Sedan 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 S3 doesn’t offer automatic braking for stationary objects directly to the rear.

The 3 Series Sedan offers an optional Surround View to allow the driver to see objects all around the vehicle on a screen. The S3 only offers a rear monitor and front and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the sides.

The 3 Series 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 S3 doesn’t offer a driver alert monitor.

Both the 3 Series Sedan and the S3 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, post-collision automatic braking systems, daytime running lights, rearview cameras, available all wheel drive, lane departure warning systems, blind spot warning systems and rear cross-path warning.

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. Audi only pays for the first scheduled maintenance visit on the S3.

There are over 14 percent more BMW dealers than there are Audi dealers, which makes it easier should you ever need service under the 3 Series Sedan’s warranty.

To reliably start during all conditions and help handle large electrical loads, the 3 Series Sedan has a standard 720-amp battery. The S3’s 380-amp battery isn’t as powerful.

J.D. Power and Associates rated the 3 Series Sedan third among compact premium cars in their 2024 Initial Quality Study. The S3 isn’t in the top three in its category.

J.D. Power and Associates’ 2024 Initial Quality Study of new car owners surveyed provide the statistics that show that BMW vehicles are better in initial quality than Audi vehicles. With 36 fewer problems per 100 vehicles, JD Power ranks BMW higher than Audi.

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 Audi With 85 fewer problems per 100 vehicles in the first three years of ownership, J.D. Power ranks BMW higher than Audi.

From surveys of all its subscribers, Consumer Reports’ January 2024 Auto Issue reports that BMW vehicles are more reliable than Audi vehicles. Consumer Reports ranks BMW 10 places higher in reliability than Audi.

The M340i’s standard 3.0 turbo 6-cylinder hybrid produces 80 more horsepower (386 vs. 306) and 103 lbs.-ft. more torque (398 vs. 295) than the S3’s 2.0 turbo 4-cylinder.

On the EPA test cycle the 3 Series Sedan gets better mileage than the S3:

Regenerative brakes improve the 3 Series Sedan’s fuel efficiency by converting inertia back into energy instead of wasting it. The S3 doesn’t offer a regenerative braking system.

The 3 Series Sedan’s standard fuel tank has 1.1 gallons more fuel capacity than the S3 (15.6 vs. 14.5 gallons).

In its Green Vehicle Guide, the U.S. Environmental Protection Agency (EPA) rates the BMW 3 Series Sedan higher (6 to 7 out of 10) than the Audi S3 (5). This means the 3 Series Sedan produces up to 8 pounds less smog-producing pollutants than the S3 every 15,000 miles.

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 S3.

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 S3; 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 S3 don’t have a run-flat feature, either.

For a smoother ride and more stable handling, the 3 Series Sedan’s wheelbase is 8.6 inches longer than on the S3 (112.2 inches vs. 103.6 inches).

For better handling and stability, the track (width between the wheels) on the 3 Series Sedan is 1.4 inches wider in the front and 1.9 inches wider in the rear than on the S3.

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 S3 (.31) and many sports cars. A more efficient exterior helps keep the interior quieter and helps the 3 Series Sedan get better fuel mileage.

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 S3 doesn’t offer active grille shutters.

The 3 Series Sedan has 1.9 inches more front headroom, .8 inches more front legroom, 1.2 inches more front shoulder room, 1 inch more rear headroom and 1.6 inches more rear shoulder room than the S3.

The 3 Series Sedan has a much larger trunk than the S3 (16.9 vs. 8.3 cubic feet).

Pulling a handle automatically lowers the 3 Series Sedan’s rear seats, to make changing between passengers and cargo easier. The S3 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 S3’s non-lockable folding seat and non-lockable remote release defeat cargo security.

The engine in the 3 Series Sedan is mounted longitudinally (North-South), instead of sideways, as in the S3. This makes it easier to service and maintain, because the accessory belts are in front.

The S3’s cornering lamps activate a lamp on the front corner when the turn signal is activated. The 3 Series Sedan’s optional adaptive cornering lights turn the actual headlight unit up to several degrees, depending on steering wheel angle and vehicle speed. This lights a significant distance into corners at any speed.

The 3 Series Sedan’s sun-visors swivel front-to-side to block glare from the side windows. The S3’s visors are fixed into the windshield header.

The BMW 3 Series Sedan has power folding mirrors that offer unparalleled convenience while maneuvering in tight places or parked. With the mirrors folded it’s easier to walk past and help prevent parking damage. The mirrors can be quickly unfolded when the driver is ready to leave. Power folding mirrors costs extra on the S3.

Both the 3 Series Sedan and the S3 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 S3.

On extremely cold winter days, the 3 Series Sedan’s optional heated steering wheel provides comfort, allowing the driver to steer safely and comfortably before the car heater warms up. The S3 doesn’t offer a heated steering wheel.

The BMW 3 Series Sedan has a standard Homelink wireless remote control system for garage door operation and device management, conveniently located on the rear view mirror. Homelink® eliminates the need for separate garage door openers and associated risks of losing, breaking, or having dead batteries. Audi charges extra for Homelink® on the S3.

To quickly and conveniently keep personal devices charged without cables tangling and wearing out, the BMW 3 Series has a standard wireless phone charging system (Qi) in the center console. Wireless charging costs extra on the S3.

The 3 Series Sedan’s optional Parking Assistant Plus can parallel park or back into a parking spot by itself, starting, stopping and changing direction automatically. The S3’s automatic parking system requires operating the brakes and transmission to safely park.

The 3 Series Sedan is available in both rear-wheel drive and all-wheel drive configurations. The S3 doesn’t offer a two-wheel drive configuration.

Consumer Reports® recommends the BMW 3 Series Sedan, based on reliability, safety and performance.

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 S3 isn’t in the top three.

The BMW 3 Series outsold the Audi A3/S3/RS 3 by over two to one during 2023.