At first glance, the 2007 Jaguar XK’s 4.2-liter V8 engine would seem to be slightly underpowered, making 300 horsepower at 6,000 rpm. Consider, for example, that the 2006 Cadillac XLR generates 20 horses more at 6,400 rpm, and the BMW 650Ci generates a whopping 60 more horsepower at 6,300 rpm. Torque ratings are competitive across the board, with the Jaguar XK rated at 310 lb.-ft. at 4,100 rpm. The 650Ci offers more torque, 360 lb. ft. to be exact, but those numbers don’t tell the whole story, as the Jaguar XK coupe weighs almost 150 lbs. less than the BMW 650Ci, and the convertible XK is a lithe 513 lbs. lighter than the BMW. According to the respective automakers, the 2007 Jaguar XK coupe’s time of 5.9 seconds is 6/10ths of a second off the BMW’s time of 5.3 seconds, and the convertible, at 6.0 seconds, is 4/10ths of a second off the BMW 650Ci convertible’s time of 5.6 seconds. If that engine powering the XK sounds familiar, that’s because it is: it’s the same powerplant inside the current XK8, but with six more horsepower thanks to a new fuel injection system.

Just one transmission is offered in the new XK, but it’s a beauty. Jaguar’s six-speed sequential automatic, significantly revised with paddle shifters in lieu of the traditional “J” gate and offering both Drive and Drive Sport (DS) modes, features faster shift times thanks to dual clutches that control the amount of torque delivered during upshifts, according to Jaguar engineers. This means that there is no torque interrupt while shifting, making the total shift sequence take all of 600 milliseconds, according to Jaguar. What this means to drivers is that shifts are virtually instantaneous. Another feature of the transmission is its adaptive gearing, based on driver input and road conditions.

Even though the 2007 Jaguar XK’s engine is more powerful and the transmission is improved, the most notable change to the new XK is the actual body of the car. The all-aluminum unibody, the manufacture of which is largely accomplished via bonding and riveting techniques, is lighter and stiffer than the previous XK8 – and the competition, according to Jaguar. What’s new to the XK isn’t necessarily new to Jaguar, however, as much of the underpinnings are shared with the Jaguar XJ sedan. The technology is new to this Jaguar, however, and a quick glance at curb weight specs across the luxury sports coupe/convertible class bears out the benefits.

A drive in the XK confirms that the body, as coupe or convertible, is quite stiff. The body’s performance is enhanced by a suspension setup which, as with the previous version, features double wishbones up front and a short- and long-arm configuration in back. What’s new is an updated version of Jaguar’s Computer Active Technology (CATS). CATS is a two-stage adaptive damping system, helping to automatically balance ride and handling. In the previous XK8, CATS provided front and rear pitch control; this new system now regulates all four dampers helping to control body roll as well as pitch. The ride is also enhanced by speed-sensitive and mechanically-assisted steering, which provides plenty of feedback.

Standard wheels for the XK are 18-inch alloys, with 19 and 20-inch wheels available. Standard tires are Continentals sized P245/45ZR18 up front and P255/45ZR18 in back, with optional Dunlops measuring P245/40ZR19 or P255/35ZR20 in front, with P275/35ZR19 or P285/30ZR20 rubber in the rear. Nineteen-inch run flats are also available. Brakes are ventilated discs all around, with a four-channel Anti-lock Brake System (ABS) with Brake Assist and Electronic Brakeforce Distribution (EBD).