The XJR is powered by the supercharged version of the 4.0 L V8. It is also equipped with sport suspension, wider wheels and tyres, and matte-black exterior window trim, except in the United States market, where the XJR was given chrome window frames and rain gutters. Like the Sport model, the XJR has a body-coloured radiator grille surround; it is with a stainless-steel mesh insert rather than the normal vanes. Other exterior touches include the XJR rear badging and larger exhaust outlets. 

Available on late XJR models was an R1 performance option. This included 18 inches BBS wheels, larger Brembo brakes with cross-drilled rotors, and re-tuned suspension. The XJR was capable of reaching 97 km/h (60 mph) from a standstill in 5.6 seconds, with an electronically limited top speed of 249 km/h (155 mph). In 2001, to commemorate the 100th anniversary of Sir William Lyons’ birth, Jaguar produced five hundred examples of a special-edition model named the XJR 100. Only available in the Anthracite exterior colour with charcoal leather upholstery, the interior is trimmed with contrasting red stitching and birdseye maple. It is fitted with a leather-covered sports steering wheel and MOMO shift knob. The XJR 100 uses the Brembo brakes otherwise found on the R1-equipped XJR and 19-inch Montreal-style wheels manufactured by BBS.

engine	Supercharged V8
valvetrain	DOHC 4 Valves / Cyl
displacement	3996 cc / 243.9 in³
bore	86 mm / 3.39 in
stroke	86 mm / 3.39 in
compression	8.9:1
power	267 kw / 358.0 bhp @ 6150 rpm
specific output	89.59 bhp per litre
bhp/weight	bhp per tonne
torque	505 nm / 372.5 ft lbs @ 3600 rpm
front tires	255/40ZR18
rear tires	255/40ZR18
f brake size	mm / in
r brake size	mm / in
front wheels	F 45.7 x 20.3 cm / 18.0 x 8.0 in
rear wheels	R 45.7 x 20.3 cm / 18.0 x 8.0 in
curb weight	1845 kg / 4068 lbs
wheelbase	2870 mm / 113.0 in
length	5023 mm / 197.8 in
width	2078 mm / 81.8 in
height	1345 mm / 53.0 in
transmission	5-Speed Auto
gear ratios	:1
final drive	3.06:1
top speed	~250 kph / 155.3 mph
0 – 60 mph	~5.5 second