The X3 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 Cayenne doesn’t offer a whiplash protection system.
The X3 has standard BMW Assist, which uses a global positioning satellite (GPS) receiver and a cellular system to remotely unlock your doors if you lock your keys in, help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The Cayenne doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies, so if you’re involved in an accident and you’re incapacitated help may not come as quickly.
Both the X3 and the Cayenne have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front seatbelt pretensioners, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights, front parking sensors, available all wheel drive, crash mitigating brakes, lane departure warning systems, blind spot warning systems and around view monitors.
The X3’s corrosion warranty is 2 years longer than the Cayenne’s (12 vs. 10 years).
BMW pays for scheduled maintenance on the X3 for 4 years and 50,000 miles. BMW will pay for oil changes, lubrication and any other required maintenance. Porsche doesn’t pay scheduled maintenance for the Cayenne.
There are over 74 percent more BMW dealers than there are Porsche dealers, which makes it much easier should you ever need service under the X3’s warranty.
On the EPA test cycle the X3 xDrive28d gets better fuel mileage than the Cayenne Diesel (27 city/34 hwy vs. 20 city/29 hwy).
On the EPA test cycle the X3 xDrive35i xDrive 6 cyl. gets better fuel mileage than the Cayenne S V6 (19 city/27 hwy vs. 17 city/24 hwy).
Regardless of its engine, regenerative brakes improve the X3’s fuel efficiency by converting inertia back into energy instead of wasting it. Porsche only offers a regenerative brake system on the Cayenne Hybrid.
The X3 stops shorter than the Cayenne:
60 to 0 MPH
The X3’s standard tires provide better handling because they have a lower 50 series profile (height to width ratio) that provides a stiffer sidewall than the Cayenne’s standard 55 series tires.
Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires standard on the X3 can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The Cayenne doesn’t offer run-flat tires.
The BMW X3 may be more efficient, handle and accelerate better because it weighs about 550 to 950 pounds less than the Porsche Cayenne.
The X3 is 7.7 inches shorter than the Cayenne, making the X3 easier to handle, maneuver and park in tight spaces.
The X3 has 1.1 inches more front headroom, .2 inches more rear headroom, .8 inches more rear legroom and .7 inches more rear shoulder room than the Cayenne.
The X3 has a much larger cargo area with its rear seat up than the Cayenne with its rear seat up (27.6 vs. 23.7 cubic feet). The X3 has a much larger cargo area with its rear seat folded than the Cayenne with its rear seat folded (63.3 vs. 62.9 cubic feet).
To make loading groceries and cargo easier when your hands are full, the X3’s available cargo door can be opened and closed just by kicking your foot under the back bumper, leaving your hands completely free. The Cayenne doesn’t offer a hands-free gesture to open its cargo door, forcing you to put cargo down if your hands are full.
The X3 offers an optional heads-up display which projects speed and other key instrumentation readouts in front of the driver’s line of sight, allowing drivers to view information without diverting their eyes from the road. The Cayenne doesn’t offer a heads-up display.
If the windows are left down on the X3 the driver can raise them all using the key in the outside lock cylinder. On a hot day the driver can lower the windows from outside the vehicle using the key in the outside lock cylinder or the keyless remote. The driver of the Cayenne can only operate the windows from inside the vehicle, with the ignition on.
When the X3 is put in reverse, the passenger rearview mirror tilts from its original position. This gives the driver a better view of the curb during parallel parking maneuvers. Shifting out of reverse puts the mirror into its original position. The Cayenne’s mirror doesn’t automatically adjust for backing.
Optional BMW Apps for the X3 allows the driver and passengers access to select programs on their smartphones, including reading text messages aloud, playing internet radio stations, tagging songs to buy them later, following twitter accounts and other connected activities without taking their eyes off the road or their hands from the wheel. The Cayenne doesn’t offer factory integrated smartphone program access.
The X3’s optional Parking Assistant can parallel park or back into a parking spot by itself, with the driver only controlling speed with the brake pedal. The Cayenne doesn’t offer an automated parking system.
Insurance will cost less for the X3 owner. The Complete Car Cost Guide estimates that insurance for the X3 will cost $1800 to $6775 less than the Cayenne over a five-year period.
Intellichoice estimates that five-year ownership costs (depreciation, financing, insurance, fuel, fees, repairs and maintenance) for the BMW X3 will be $19189 to $60208 less than for the Porsche Cayenne.
Consumer Reports® recommends both the BMW X3 and the Porsche Cayenne, based on reliability, safety and performance.
The BMW X3 outsold the Porsche Cayenne by 76% during the 2015 model year.