Certified Benz & Beemer Compares 2004 Jaguar XK VS 2004 Porsche Boxster Near Scottsdale, AZ

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2004 Jaguar XK

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2004 Porsche Boxster

Safety Comparison

Using vehicle speed sensors and seat sensors, smart airbags in the XK deploy with different levels of force or don’t deploy at all to help better protect passengers of all sizes in different collisions. The XK’s side airbags will shut off if a child is leaning against the door. The Boxster’s airbags don’t have smart features and will always deploy full force.

The XK has standard Dynamic Stability Control (DSC), which uses the antilock brake hardware along with powerful software and additional sensors to detect the beginning of a skid. The DSC then intervenes by automatically applying the brake at one appropriate wheel, preventing a skid. A skid prevention system costs extra on the Boxster.

Both the XK and the Boxster have standard driver and passenger frontal airbags, front side-impact airbags, head airbags, front seatbelt pretensioners and four wheel antilock brakes.

The Jaguar XK weighs 780 to 1231 pounds more than the Porsche Boxster. The NHTSA advises that heavier cars are much safer in collisions than their significantly lighter counterparts. Lighter cars are also affected more by crosswinds.

Warranty Comparison

Jaguar pays for scheduled maintenance on the XK for 4 years and 50,000 miles. Jaguar will pay for oil changes, tire rotation, lubrication and any other scheduled maintenance. Porsche doesn’t pay scheduled maintenance for the Boxster.

Engine Comparison

The XK’s standard 4.2 DOHC V8 produces 66 more horsepower (294 vs. 228) and 111 lbs.-ft. more torque (303 vs. 192) than the Boxster’s standard 2.7 DOHC 6 cyl. The XK’s 4.2 DOHC V8 produces 36 more horsepower (294 vs. 258) and 74 lbs.-ft. more torque (303 vs. 229) than the Boxster S’ standard 3.2 DOHC 6 cyl. The XKR’s standard 4.2 supercharged DOHC V8 produces 132 more horsepower (390 vs. 258) and 170 lbs.-ft. more torque (399 vs. 229) than the Boxster S’ standard 3.2 DOHC 6 cyl.

For more instantaneous acceleration and better engine flexibility in any gear, the XK’s engines produce their peak torque at lower RPM’s than the Boxster:


XK 4.2 DOHC V8

4100 RPM

XKR 4.2 supercharged DOHC V8

3500 RPM

Boxster 2.7 DOHC 6 cyl.

4750 RPM

Boxster S 3.2 DOHC 6 cyl.

4500 RPM

Fuel Economy and Range Comparison

The XK has 3 gallons more fuel capacity than the Boxster (19.9 vs. 16.9 gallons), for longer range between fill-ups.

Brakes and Stopping Comparison

For better stopping power the XKR’s front brake rotors are larger than those on the Boxster:



Boxster S

Front Rotors

13.98 inches

11.7 inches

12.53 inches

Rear Rotors

13 inches

11.5 inches

11.78 inches

The XK’s standard brakes have 11% more swept area (the area covered by the brake pads) than the Boxster (535.8 vs. 484 square inches), so the XK has more braking power available. The XKR’s brakes have 15% more swept area (the area covered by the brake pads) than the Boxster S (558 vs. 484 square inches), so the XKR has more braking power available.

In an emergency stopping situation, many drivers don’t press the brakes with enough force to stop the vehicle in the shortest distance. Whatever factors cause this tendency, the XK has a standard brake assist system to detect emergency braking situations (by how hard and how quickly the brake pedal is pressed) and then automatically apply maximum braking immediately in order to help prevent a collision. The Boxster doesn’t offer a brake assist feature.

The XK stops much shorter than the Boxster:



70 to 0 MPH

166 feet

179 feet

Car and Driver

60 to 0 MPH

114 feet

119 feet

Motor Trend

Tires and Wheels Comparison

For better traction, the XK has larger standard tires than the Boxster (F:245/45R18 & R:255/45R18 vs. F:205/55R16 & R:225/50R16). The XKR’s optional tires are larger than the largest tires available on the Boxster (F:255/35R20 & R:285/30R20 vs. F:225/40R18 & R:265/35R18).

The XK’s standard tires provide better handling because they have a lower 45 series profile (height to width ratio) which provides a stiffer sidewall than the Boxster’s standard 55 series front and 50 series rear tires. The XKR’s optional 255/35R20 front and 285/30R20 rear tires have a lower 35 series front and 30 series rear profile than the Boxster’s optional 40 series front and 35 series rear tires.

For better ride, handling and brake cooling the XK has standard 18 inch wheels. Smaller 16 inch wheels are standard on the Boxster. The XKR’s optional 20 inch wheels are larger than the 18 inch wheels optional on the Boxster.

Suspension and Handling Comparison

The XK offers an optional continuously variable suspension system. Using sensors on steering angle, speed and other driver inputs, the shocks soften to improve ride, or stiffen when appropriate to aid handling on tricky roads. The Boxster’s suspension doesn’t offer adjustable shock absorbers.

For a smoother ride and more stable handling, the XK’s wheelbase is 6.8 inches longer than on the Boxster (101.9 vs. 95.1 inches).

For better handling and stability, the track (width between the wheels) on the XK is 1.6 inches wider in the front than the average track on the Boxster.

The XK8 Convertible handles at .88 G’s, while the Boxster pulls only .81 G’s of cornering force in a Car and Driver skidpad test.

Chassis Comparison

As tested by Road & Track, the interior of the XK8 Convertible is quieter than the Boxster:



At Idle

49 dB

53 dB

Full Throttle

76 dB

87 dB

70 MPH Cruising

71 dB

74 dB

Passenger Space Comparison

The XK has standard seating for 4 passengers; the Boxster can only carry 2.

Cargo Capacity Comparison

The XK Convertible has a much larger trunk than the Boxster (10.8 vs. 9.1 cubic feet).

The Boxster’s spare tire is stored in the cargo area, where it diminishes the useable cargo capacity and interferes with loading and unloading. The XK’s spare is out of the way under the trunk floor.

With its coupe or convertible body style, valet key and remote trunk release lockout, the XK offers cargo security. The Boxster’s non-lockable remote release defeats cargo security.

Ergonomics Comparison

The XK’s standard tilting steering column adjusts to different sized drivers and makes entering and exiting easier. Porsche doesn’t offer tilt steering on the Boxster.

The XK’s standard easy entry system raises the steering wheel, making it easier for the driver to get in and out. The Boxster doesn’t offer an easy entry system.

The XK’s standard power window controls are mounted on the armrest for easy access. The Boxster’s available power window controls are spread out on the center console where they can’t be seen without the driver completely removing his eyes from the road.

The XK’s standard rain-sensitive wipers adjust their speed to the amount of rainfall on the windshield. This allows the driver to concentrate on driving without constantly adjusting the wipers. The Boxster’s standard wipers only have one fixed delay setting, so the driver will have to manually switch them between slow and intermittent.

The XK has a standard automatic headlight on/off feature. When the ignition is on, the headlights automatically turn on at dusk and off after dawn. When the ignition turns off, the headlights turn off after a delay timed to allow you to securely get to your front door. The Boxster doesn’t offer automatic headlights.

The XK’s standard side window demisters help clear frost or condensation from the side windows in the winter. The Boxster doesn’t even offer side window demisters, so the driver may have to wipe the windows from the outside to gain side vision.

To keep a safe, consistent following distance, the XK 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 Boxster doesn’t offer an adaptive cruise control.

To help keep the driver’s hands on the wheel, the XK has standard steering wheel controls for the radio. The Boxster doesn’t offer steering wheel audio controls.

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