Both the 911 and the XK have standard driver and passenger frontal airbags, front side-impact airbags, head airbags, front seatbelt pretensioners, four wheel antilock brakes, electronic stability systems to prevent skidding and available traction control.
The 911’s corrosion warranty is 4 years longer than the XK’s (10 vs. 6 years).
There are over 28 percent more Porsche dealers than there are Jaguar dealers, which makes it easier to get service under the 911’s warranty.
The 911’s standard 3.6 DOHC 6 cyl. produces 31 more horsepower (325 vs. 294) than the XK’s standard 4.2 DOHC V8.
The flat cylinder configuration of the boxer engine in the 911 lowers its center of gravity, enhancing handling stability. The XK doesn’t offer a boxer engine configuration.
The 911 stops much shorter than the XK:
70 to 0 MPH
Car and Driver
For better traction and acceleration, the 911 has larger standard rear tires than the XK (265/40R18 vs. 255/45R18). The 911 S’ rear tires are larger than the largest rear tires available on the XK (295/40R19 vs. 285/30R20).
The 911’s standard tires provide better handling because they have a lower 40 series profile (height to width ratio) which provides a stiffer sidewall than the XK’s standard 45 series tires. The 911 S’ 235/30R19 front tires have a lower 30 series profile than the XKR’s optional 35 series front tires.
The 911 has standard front and rear gas-charged shocks for better control over choppy roads. The XK’s suspension doesn’t offer gas-charged shocks.
For better handling and stability, the track (width between the wheels) on the 911 is 1.4 inches wider in the rear than on the XK.
The 911 S handles at .97 G’s, while the XKR Coupe pulls only .88 G’s of cornering force in a Car and Driver skidpad test.
The Porsche 911 may be more efficient, handle and accelerate better because it weighs about 700 to 800 pounds less than the Jaguar XK.
The 911 is 1 foot shorter than the XK, making the 911 easier to handle, maneuver and park in tight spaces.
The design of the Porsche 911 amounts to more than styling. The 911 offers aerodynamic coefficients of drag from .28 to .29 Cd (depending on bodystyle and options). That is significantly lower than the XK (.345 to .36). A more efficient exterior helps the 911 go faster and keeps the interior quieter. It also helps the 911 get better fuel mileage.
The 911’s standard rear seats fold to accommodate long and bulky cargo. The XK doesn’t offer folding rear seats.
The 911’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 XK does not have an oil pressure gauge.
The 911’s power windows raise and lower automatically with one touch, especially convenient at tollbooths or drive-up windows. The power windows on the XK don’t raise automatically.
If the windows are left down on the 911 the driver can raise them all using the key in the outside lock cylinder. The driver of the XK can only operate the windows from inside the vehicle, with the ignition on.
The 911 has a standard center folding armrest for the rear passengers. A center armrest helps make rear passengers more comfortable. The XK doesn’t offer a rear seat center armrest.
A built-in pollen filter with a charcoal activated canister removes pollen, exhaust fumes and other pollutants from the 911’s passenger compartment. This helps prevent lung and/or sinus irritation, which can trigger allergies or asthma. The XK doesn’t offer a filtration system.
The 911’s standard separate stalk mounted cruise control on/off switch is conveniently located with the rest of the cruise controls. The XK’s standard cruise control must be turned on with a hard to find switch on the dashboard.