The 1997 XK8 (project code X100) was available with either a supercharged 370 hp (276 kW) or naturally aspirated 290 hp (216 kW) engine. The supercharged variant is known as the XKR. The first-generation XK series shares its platform with the Aston Martin DB7. Both cars are derived from the Jaguar XJS, though the platform has been extensively changed.
In 2005 the grille design of the XKR was refreshed. Jaguar unveiled an all-new 2006 car (project code X150), called simply the "XK", at the Frankfurt Motor Show in September 2005. It uses the new all-aluminium monocoque chassis developed from the 2005 Advanced Lightweight Coupé (ALC) concept car and is offered as both a coupé or convertible. In the opposite manner to the way convertibles are traditionally designed, the coupé is based on the convertible. This meant that the engineers could design the convertible without the drawbacks of the car looking like, and actually being, a coupé with the top chopped off. It also meant that minimal additional weight was required to maintain the structural rigidity lost with the removal of the roof (1,635 kg (3,600 lb) kerb weight for the convertible versus 1,595 kg (3,520 lb) for the coupé). This makes the XK convertible exceptionally rigid and lightweight for a car of its type, offering an extremely impressive driving experience. The XK convertible was introduced at the 2006 North American International Auto Show. It features a conventional cloth top that will open or close in 18 seconds.Source: Wikipedia.