Compare the2023 BMW 8 SeriesVS 2023 Porsche 911

The 8 Series’ pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The 911 doesn’t offer pre-crash pretensioners.

The BMW 8 Series 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 911 doesn’t offer knee airbags.

The 8 Series 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 911 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.

The 8 Series’ 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 911.

To help make backing out of a parking space safer, the 8 Series’ optional Cross Traffic Warning uses sensors in the rear to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The 911 doesn’t offer a rear cross-path warning system.

The 8 Series’ 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 911 doesn’t offer a driver alert monitor.

Both the 8 Series and the 911 have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, rearview cameras, available blind spot warning systems and rear parking sensors.

BMW pays for scheduled maintenance on the 8 Series for 2 years and 26000 miles longer than Porsche pays for maintenance for the 911 (3/36,000 vs. 1/10,000).

There are over 80 percent more BMW dealers than there are Porsche dealers, which makes it much easier should you ever need service under the 8 Series’ warranty.

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 Porsche vehicles. J.D. Power ranks BMW above average in initial quality. With 35 more problems per 100 vehicles, Porsche is rated below average.

The 8 Series has more powerful engines than the 911:

As tested in Car and Driver the M850i 4.4 turbo V8 is faster than the Porsche 911 3.0 turbo 6-cylinder (automatics tested):

On the EPA test cycle the 8 Series Coupe gets better mileage than the 911 Coupe:

On the EPA test cycle the 8 Series Convertible gets better mileage than the 911 Cabriolet:

Regenerative brakes improve the 8 Series’ fuel efficiency by converting inertia back into energy instead of wasting it. The 911 doesn’t offer a regenerative braking system.

The 8 Series has 1.1 gallons more fuel capacity than the 911’s standard fuel tank (18 vs. 16.9 gallons), for longer range between fill-ups.

For better stopping power the 8 Series’ standard brake rotors are larger than those on the 911:

For better traction, the 8 Series has larger front tires than the 911 (245/35R20 vs. 235/40R19).

The 8 Series’ standard 245/40R19 front and 275/35R19 rear tires provide better handling because they have a lower 40 series front and 35 series rear profile (height to width ratio) that provides a stiffer sidewall than the 911 Dakar’s standard 45 series front and 40 series rear tires.

Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires available on the 8 Series can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The 911 doesn’t offer run-flat tires.

The M850i offers an available active suspension system, which counteracts cornering forces actively, limiting body roll and improving handling and stability. Porsche doesn’t offer an active suspension on the 911.

For a smoother ride and more stable handling, the 8 Series’ wheelbase is 14.6 inches longer than on the 911 (111.1 inches vs. 96.5 inches). The 8 Series’ wheelbase is 14.4 inches longer than on the 911 GT3 (111.1 inches vs. 96.7 inches).

For better handling and stability, the track (width between the wheels) on the 8 Series is 1.4 inches wider in the front and 3 inches wider in the rear than the average track on the 911.

The 8 Series’ front to rear weight distribution is more even (50.3% to 49.7%) than the 911’s (39.5% to 60.5%). This gives the 8 Series more stable handling and braking.

The 8 Series has 8 cubic feet more passenger volume than the 911 (81 vs. 73).

The 8 Series Coupe has 1 inch more front headroom, 4.6 inches more front shoulder room, 1.1 inches more rear headroom and 2.3 inches more rear legroom than the 911 Coupe.

The 8 Series Coupe has a much larger trunk than the 911 Coupe with its rear seat up (14.8 vs. 4.6 cubic feet). The 8 Series has a much larger trunk with its rear seat folded than the 911 Coupe with its rear seat folded (14.8 vs. 13.8 cubic feet).

The 8 Series Convertible has a much larger trunk with its top down than the 911 Cabriolet with its top down (12.4 vs. 4.6 cubic feet). The 8 Series Convertible has a much larger trunk than the 911 Cabriolet with its top up (12.4 vs. 10.4 cubic feet).

Pulling a handle automatically lowers the 8 Series’ rear seats, to make changing between passengers and cargo easier. The 911 doesn’t offer automatic folding seats.

With its coupe body style, locking rear seatbacks and remote trunk release lockout, the 8 Series offers cargo security. The 911’s non-lockable folding seat defeats cargo security.

To make loading and unloading groceries and cargo easier when your hands are full, the 8 Series’ power trunk can be opened or closed just by kicking your foot under the back bumper, leaving your hands completely free. The 911 doesn’t offer a power or hands-free opening trunk.

The 8 Series has a standard remote vehicle starting system, so the vehicle can be started from inside the driver's house. This allows the driver to comfortably warm up the engine before going out to the vehicle. The climate system will also automatically heat or cool the interior. The 911 doesn’t offer a remote starting system.

Unlike the driver-only memory system optional at extra cost in the 911, the 8 Series has standard driver and passenger memory, so that when drivers switch, the memory setting adjusts the driver’s seat, steering wheel position, outside mirror angle, climate settings and radio stations and the front passenger seat also adjusts to the new passenger’s preset preferences.

The 8 Series’ standard easy entry system raises the steering wheel, making it easier for the driver to get in and out. An easy entry system costs extra on the 911.

The 8 Series has a standard heads-up display that projects speed, tachometer, warning and navigation instruction readouts in front of the driver’s line of sight, allowing drivers to view information without diverting their eyes from the road. The 911 doesn’t offer a heads-up display.

If the windows are left open on the 8 Series the driver can close them all at the outside door handle or from a distance using the remote. On a hot day the driver can lower the windows from a distance using the keyless remote. The driver of the 911 can only operate the windows from inside the vehicle, with the ignition on.

The 8 Series has a standard heated steering wheel to take the chill out of steering on extremely cold winter days before the car heater warms up. A heated steering wheel costs extra on the 911.

The BMW 8 Series comes in coupe, convertible and sedan bodystyles; the Porsche 911 isn’t available as a sedan.

Insurance will cost less for the 8 Series owner. The Complete Car Cost Guide estimates that insurance for the 8 Series will cost $360 less than the 911 over a five-year period.