Both the Cayman and the M4 have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, traction control and electronic stability systems to prevent skidding.
To reliably power the ignition and other systems and to recharge the battery, the Cayman has a standard 2100-amp alternator. The M4’s 209-amp alternator isn’t as powerful.
J.D. Power and Associates’ 2013 Initial Quality Study of new car owners surveyed provide the statistics that show that Porsche vehicles are better in initial quality than BMW vehicles. J.D. Power ranks Porsche first in initial quality, above the industry average. With 34 more problems per 100 vehicles, BMW is ranked 18th, below the industry average.
J.D. Power and Associates’ 2013 survey of the owners of three-year-old vehicles provides the long-term dependability statistics that show that Porsche vehicles are more reliable than BMW vehicles. J.D. Power ranks Porsche second in reliability, above the industry average. With 39 more problems per 100 vehicles, BMW is ranked 16th.
The flat cylinder configuration of the boxer engine in the Cayman lowers its center of gravity, enhancing handling stability. The M4 doesn’t offer a boxer engine configuration.
Regenerative brakes improve the Cayman’s fuel efficiency by converting inertia back into energy instead of wasting it. The M4 doesn’t offer a regenerative braking system.
The Cayman has 1.1 gallons more fuel capacity than the M4 (16.9 vs. 15.8 gallons), for longer range between fill-ups.
For better ride, handling and brake cooling the Cayman offers optional 20-inch wheels. The M4’s largest wheels are only 19-inches.
For better maneuverability, the Cayman’s turning circle is 4 feet tighter than the M4’s (36 feet vs. 40 feet).
The Porsche Cayman may be more efficient, handle and accelerate better because it weighs about 600 to 650 pounds less than the BMW M4.
The Cayman is 1 foot shorter than the M4, making the Cayman easier to handle, maneuver and park in tight spaces.
To almost totally eliminate engine vibration in the passenger area, the Cayman w/Sport Chrono has an electronically controlled liquid-filled front engine mount and conventional liquid-filled engine mounts (standard liquid front mount on other versions of the Cayman). A computer-controlled electric current in the liquid changes its viscosity, allowing the mount to dampen the engine completely at all RPMs. The M4 uses conventional solid rubber engine mounts.
The design of the Porsche Cayman amounts to more than styling. The Cayman has an aerodynamic coefficient of drag of .3 Cd. That is significantly lower than the M4 (.34). A more efficient exterior helps the Cayman go faster and keeps the interior quieter. It also helps the Cayman get better fuel mileage.
The Cayman’s optional easy entry system raises the steering wheel and glides the driver’s seat back when the door is unlocked or the ignition is switched off, making it easier for the driver to get in and out. The M4 doesn’t offer an easy entry system.
The Cayman’s instruments include an oil pressure gauge and a temperature gauge – which could save your engine! Often ‘idiot lights’ don’t warn you until damage has been done. The M4 does not have an oil pressure gauge.
The Cayman’s front power windows open or close fully with one touch of the switches, making it more convenient at drive-up windows and toll booths, or when talking with someone outside the car. The M4’s passenger windows don’t open or close automatically.
To improve rear visibility by keeping the rear window clear, the Cayman offers an optional rear wiper. The M4 doesn’t offer a rear wiper.
The Cayman’s optional air conditioned front seats cool the driver and front passenger and help take the sting out of hot leather in Summer. The M4 doesn’t offer air conditioned front seats.
To keep a safe, consistent following distance, the Cayman PDK offers an optional Adaptive Cruise Control, which alters the speed of the vehicle without driver intervention. This allows the driver to use cruise control more safely without constantly having to disengage it when approaching slower traffic. The M4 doesn’t offer an adaptive cruise control.