Compare the2024 BMW 8 SeriesVS 2024 Porsche 718 Cayman

Safety
Warranty
Reliability
Engine
Fuel Economy and Range
Transmission and Drivetrain
Brakes and Stopping
Tires and Wheels
Suspension and Handling
Chassis
Passenger Space
Cargo Capacity
Ergonomics
Model Availability
Recommendations

Safety

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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 718 Cayman doesn’t offer pre-crash pretensioners.

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 718 Cayman 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 8 Series 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 718 Cayman doesn’t offer backup collision prevention brakes.

The 8 Series offers all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The 718 Cayman doesn’t offer all-wheel drive.

The 8 Series’ 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 718 Cayman doesn’t offer a lane departure warning system.

The 8 Series offers an optional Surround View Camera to allow the driver to see objects all around the vehicle on a screen. The 718 Cayman 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.

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 718 Cayman 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 718 Cayman doesn’t offer a driver alert monitor.

Both the 8 Series and the 718 Cayman 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, daytime running lights, rearview cameras and available blind spot warning systems.

The BMW 8 Series weighs 668 to 1651 pounds more than the Porsche 718 Cayman. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts.

Warranty

BMW pays for scheduled maintenance on the 8 Series for 2 years and 26000 miles longer than Porsche pays for maintenance for the 718 Cayman (3/36,000 vs. 1/10,000).

There are over 76 percent more BMW dealers than there are Porsche dealers, which makes it much easier should you ever need service under the 8 Series’ warranty.

Reliability

J.D. Power and Associates rated the 8 Series first among large premium cars in their 2023 Initial Quality Study. The 718 Cayman was rated third in its category.

Engine

The 8 Series has more powerful engines than the 718 Cayman:

	Horsepower	Torque
840i 3.0 turbo 6-cylinder	335 HP	369 lbs.-ft.
M850i 4.4 turbo V8	523 HP	553 lbs.-ft.
718 Cayman 2.0 turbo 4-cylinder	300 HP	280 lbs.-ft.
718 Cayman S 2.5 turbo 4-cylinder	350 HP	309 lbs.-ft.
718 Cayman GTS 4.0 4.0 GT3 6-cylinder	394 HP	309 lbs.-ft.
718 Cayman GT4 RS 4.0 DOHC 6-cylinder	493 HP	331 lbs.-ft.

As tested in Car and Driver the M850i 4.4 turbo V8 is faster than the Porsche 718 Cayman (automatics tested):

	8 Series	718 Cayman S	718 Cayman GTS 4.0
Zero to 60 MPH	3.3 sec	3.6 sec	3.4 sec
Quarter Mile	11.5 sec	12 sec	11.6 sec

Fuel Economy and Range

On the EPA test cycle the 8 Series Coupe gets better mileage than the 718 Cayman:

			MPG
8 Series Coupe
RWD	Auto	3.0 turbo 6-cyl.	21 city/29 hwy
AWD	Auto	3.0 turbo 6-cyl.	21 city/29 hwy
		4.4 turbo V8	17 city/24 hwy
718 Cayman
RWD	Manual	2.0 turbo flat-4	20 city/25 hwy
		2.5 turbo flat-4	19 city/24 hwy
		GTS 4.0 DOHC flat-6	17 city/24 hwy
	Auto	2.0 turbo flat-4	21 city/27 hwy
		2.5 turbo flat-4	19 city/25 hwy
		GTS 4.0 DOHC flat-6	19 city/24 hwy
		GT4 RS 4.0 DOHC flat-6	15 city/19 hwy

The 8 Series has 3.8 gallons more fuel capacity than the 718 Cayman’s standard fuel tank (18 vs. 14.2 gallons), for longer range between fill-ups. The 8 Series has 1.1 gallons more fuel capacity than the 718 Cayman’s optional fuel tank (18 vs. 16.9 gallons).

Transmission and Drivetrain

The BMW 8 Series comes standard with an automatic transmission, for driver comfort, especially in the city. Automatic costs extra on the 718 Cayman.

An eight-speed automatic is standard on the BMW 8 Series, for better acceleration and lower engine speed on the highway. Only a seven-speed automatic is available for the 718 Cayman.

All wheel drive, available in the 8 Series, provides the best traction for acceleration in wet, dry, and icy conditions. In corners, all wheel drive allows both outside wheels to provide power, balancing the car. This allows for better handling. The Porsche 718 Cayman is not available with all wheel drive.

Brakes and Stopping

For better stopping power the 8 Series’ standard brake rotors are larger than those on the 718 Cayman:

	8 Series	718 Cayman
Front Rotors	13.7 inches	13 inches
Rear Rotors	13.6 inches	11.8 inches

Tires and Wheels

For better traction, the 8 Series has larger tires than the 718 Cayman (F:245/35R20 & R:275/30R20 vs. F:235/45R18 & R:265/45R18).

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 718 Cayman’s standard 45 series tires.

For better ride, handling and brake cooling the 8 Series has standard 19-inch wheels. Smaller 18-inch wheels are standard on the 718 Cayman.

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 718 Cayman doesn’t offer run-flat tires.

Suspension and Handling

The 8 Series M850i has active sway bars, which help keep it flat and controlled during cornering, but disconnect at lower speeds to smooth the ride and offer greater off-road suspension articulation. This helps keep the tires glued to the road on-road and off. The 718 Cayman doesn’t offer an active sway bar system.

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 718 Cayman.

For a smoother ride and more stable handling, the 8 Series’ wheelbase is 13.7 inches longer than on the 718 Cayman (111.1 inches vs. 97.4 inches).

For better handling and stability, the track (width between the wheels) on the 8 Series is 4.1 inches wider in the front and 4.2 inches wider in the rear than the average track on the 718 Cayman.

Chassis

The front grille of the 8 Series uses electronically controlled shutters to close off airflow and reduce drag when less engine cooling is needed. This helps improve highway fuel economy. The 718 Cayman doesn’t offer active grille shutters.

Passenger Space

The 8 Series has standard seating for 4 passengers; the 718 Cayman can only carry 2.

The 8 Series has 33 cubic feet more passenger volume than the 718 Cayman (81 vs. 48).

Cargo Capacity

With its coupe body style, locking rear seatbacks and remote trunk release lockout, the 8 Series offers cargo security. The 718 Cayman’s hatchback body style and non-lockable remote release defeat cargo security.

To make loading and unloading groceries and cargo easier, especially for short adults, the 8 Series has a standard power trunk, which opens and closes automatically by pressing a button or just by kicking your foot under the back bumper, completely leaving your hands free. The 718 Cayman doesn’t offer a power trunk, so its trunk has to be closed manually.

Ergonomics

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 718 Cayman doesn’t offer a remote starting system.

Unlike the driver-only memory system optional at extra cost in the 718 Cayman, 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 718 Cayman.

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 718 Cayman 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 718 Cayman can only operate the windows from inside the vehicle, with the ignition on.

The 8 Series has standard Comfort Access that allows you to unlock the doors from either outside door handle, open the trunk, and start the engine, all without removing the key from the pocket or purse. Porsche Entry and Drive costs extra on the 718 Cayman.

The 8 Series’ power window, power lock, power mirror and cruise control switches are lit from behind, making them plainly visible and easier to operate at night. The 718 Cayman’s cruise control switches are unlit, making them difficult to find at night and operate safely.

The 8 Series’ LED headlights produce a white, bright light using less electricity than the 718 Cayman’s standard xenon high intensity discharge (HID) headlights. HID headlights can be slow to reach full brightness or power cycle, causing issues when flashing them to signal other vehicles; LED headlights light instantly. LED lights also last about three to four times as long.

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 718 Cayman.

To quickly and conveniently keep personal devices charged without cables tangling and wearing out, the BMW 8 Series has a standard wireless phone charging system (Qi) in the front center console. The 718 Cayman doesn’t offer wireless personal charging.

The 8 Series’ optional Parking Assistant Plus can parallel park by itself, starting, stopping and changing direction automatically. The 718 Cayman doesn’t offer an automated parking system.

Model Availability

The BMW 8 Series comes in coupe, convertible and sedan bodystyles; the Porsche 718 isn’t available as a sedan.

Recommendations

The BMW 8 Series outsold the Porsche 718 by 27% during 2023.

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