The Jaguar XK Convertible (X100) R 4.0 V8 Automatic, produced between 1998 and 2002, represented the performance pinnacle of the first-generation X100 XK8 convertible range. Positioned as the flagship model, the ‘R’ variant offered a significant power upgrade over the standard XK8, appealing to drivers seeking a more engaging and dynamic grand touring experience. Built on Jaguar’s JH8 platform, the X100 aimed to recapture the spirit of the classic Jaguar sports cars, blending British luxury with modern technology. This particular iteration, combining the supercharged 4.0-liter V8 with a five-speed automatic transmission, offered a unique balance of power and convenience within the X100 lineup.
Technical Specifications
| Brand | Jaguar |
| Model | XK |
| Generation | XK Convertible (X100) |
| Type (Engine) | R 4.0 V8 (363 Hp) Automatic |
| Start of production | 1998 |
| End of production | 2002 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 18 l/100 km (13.1 US mpg, 15.7 UK mpg, 5.6 km/l) |
| Fuel consumption (extra urban) | 9.6 l/100 km (24.5 US mpg, 29.4 UK mpg, 10.4 km/l) |
| Fuel consumption (combined) | 12.7 l/100 km (18.5 US mpg, 22.2 UK mpg, 7.9 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.6 sec |
| Acceleration 0 – 62 mph | 5.6 sec |
| Acceleration 0 – 60 mph | 5.3 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Weight-to-power ratio | 5 kg/Hp, 198.9 Hp/tonne |
| Weight-to-torque ratio | 3.6 kg/Nm, 276.7 Nm/tonne |
| Power | 363 Hp @ 6150 rpm |
| Power per litre | 90.8 Hp/l |
| Torque | 505 Nm @ 3600 rpm (372.47 lb.-ft. @ 3600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | AJ26S, AJ27S |
| Engine displacement | 3996 cm3 (243.85 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 86 mm (3.39 in.) |
| Piston Stroke | 86 mm (3.39 in.) |
| Compression ratio | 8.9:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Supercharger |
| Valvetrain | DOHC |
| Engine oil capacity | 6.5 l (6.87 US qt | 5.72 UK qt) |
| Coolant | 11.5 l (12.15 US qt | 10.12 UK qt) |
| Kerb Weight | 1825 kg (4023.44 lbs.) |
| Max. weight | 2100 kg (4629.71 lbs.) |
| Max load | 275 kg (606.27 lbs.) |
| Trunk (boot) space – minimum | 307 l (10.84 cu. ft.) |
| Fuel tank capacity | 75 l (19.81 US gal | 16.5 UK gal) |
| Length | 4760 mm (187.4 in.) |
| Width | 1829 mm (72.01 in.) |
| Height | 1306 mm (51.42 in.) |
| Wheelbase | 2588 mm (101.89 in.) |
| Front track | 1504 mm (59.21 in.) |
| Rear (Back) track | 1498 mm (58.98 in.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 5 gears, automatic transmission |
| Front suspension | Double wishbone |
| Rear suspension | Double wishbone |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Power steering | Hydraulic Steering |
| Tires size | 245/45 R18; 255/45 R18 |
Powertrain & Engine Architecture
The heart of the XK8 R was Jaguar’s AJ26S/AJ27S 4.0-liter supercharged V8 engine. This engine, a significant departure from Jaguar’s traditional inline-six designs, was a thoroughly modern powerplant. It featured a 90-degree V-angle, aluminum block and cylinder heads, and dual overhead camshafts (DOHC) with four valves per cylinder. The supercharger, a Lysholm-type twin-screw unit, provided a substantial boost in power over the naturally aspirated XK8. Fuel delivery was handled by a multi-port fuel injection system, ensuring precise fuel metering. The five-speed automatic transmission, a ZF 5HP24 unit, was chosen for its smoothness and reliability. While not as sporty as a manual transmission, it provided effortless cruising and suited the grand touring nature of the vehicle. The transmission featured adaptive shift programming, adjusting shift points based on driving style.
Driving Characteristics
The XK8 R Automatic offered a markedly different driving experience compared to the standard XK8. The supercharger delivered instant and substantial torque, resulting in brisk acceleration. The 0-60 mph time of around 5.3 seconds was a significant improvement over the naturally aspirated models. The automatic transmission, while smooth, could feel slightly hesitant during aggressive driving, particularly when downshifting. The gear ratios were tuned for comfortable cruising rather than outright performance. The suspension, while providing a comfortable ride, was firm enough to inspire confidence in corners. The rear-wheel-drive layout contributed to a balanced feel, although the car’s weight (approximately 4,023 lbs) was noticeable during hard cornering.
Equipment & Trim Levels
The ‘R’ trim level came generously equipped. Standard features included leather upholstery, power-adjustable seats with memory function, automatic climate control, a premium sound system, and alloy wheels. Wood veneer trim adorned the interior, adding to the luxurious ambiance. Optional extras included heated seats, a navigation system, and upgraded leather options. The interior design was classic Jaguar, emphasizing comfort and elegance. The dashboard layout was straightforward and user-friendly, with clearly labeled controls.
Chassis & Braking
The X100 chassis utilized a double wishbone suspension system at both the front and rear, providing a comfortable ride and good handling characteristics. The ‘R’ model benefited from slightly stiffer springs and dampers compared to the standard XK8, improving body control. Braking duties were handled by ventilated disc brakes on all four wheels, coupled with an Anti-lock Braking System (ABS). The braking system provided ample stopping power, although the car’s weight required a firm pedal input. The steering was hydraulic power-assisted rack and pinion, offering precise and responsive steering feel.
Market Reception & Comparison
The XK8 R was generally well-received by automotive critics. It was praised for its powerful engine, luxurious interior, and comfortable ride. However, some critics noted the automatic transmission’s occasional hesitancy and the car’s considerable weight. Compared to the standard XK8, the ‘R’ offered a significant performance upgrade, making it a more appealing option for drivers seeking a more engaging driving experience. Compared to rivals like the BMW 6 Series and Mercedes-Benz SL, the XK8 R offered a unique blend of British style and performance. Fuel economy, at around 18.5 US mpg combined, was typical for a high-performance grand tourer of the era.
Legacy
The Jaguar XK8 R 4.0 V8 Automatic has become a sought-after classic among Jaguar enthusiasts. The supercharged V8 engine is known for its reliability, provided it receives regular maintenance. Common issues include occasional oil leaks and sensor failures. The ZF automatic transmission is generally robust, but fluid changes are crucial for longevity. Today, well-maintained examples command a premium in the used car market. The X100 R represents a significant chapter in Jaguar’s history, marking a return to form for the brand and offering a compelling blend of luxury, performance, and British charm.
