The Jaguar XJ X308 R 4.0 V8, produced from 1997 to 2003, represented the pinnacle of the X308 series, Jaguar’s replacement for the XJ40. Positioned as the high-performance variant, the ‘R’ model aimed to blend the XJ’s traditional luxury with significantly enhanced sporting capabilities. Built upon the Jaguar XJ platform (X308), it served as the flagship model, offering a more dynamic driving experience than the standard inline-six and naturally aspirated V8 options. The X308 generation itself was a significant step forward for Jaguar, incorporating substantial aluminum construction in the chassis and body to reduce weight and improve rigidity, a first for a mass-produced Jaguar.
Technical Specifications
| Brand | Jaguar |
| Model | XJ |
| Generation | XJ (X308) |
| Type (Engine) | R 4.0 V8 32V (363 Hp) Automatic |
| Start of production | 1997 |
| End of production | 2003 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 18 l/100 km (13.1 US mpg, 15.7 UK mpg, 5.6 km/l) |
| Fuel consumption (extra urban) | 9.5 l/100 km (24.8 US mpg, 29.7 UK mpg, 10.5 km/l) |
| Fuel consumption (combined) | 12.6 l/100 km (18.7 US mpg, 22.4 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 | 5.1 kg/Hp, 196.7 Hp/tonne |
| Weight-to-torque ratio | 3.7 kg/Nm, 273.7 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 | 12 l (12.68 US qt | 10.56 UK qt) |
| Kerb Weight | 1845 kg (4067.53 lbs.) |
| Max. weight | 2260 kg (4982.45 lbs.) |
| Max load | 415 kg (914.92 lbs.) |
| Trunk (boot) space – minimum | 430 l (15.19 cu. ft.) |
| Fuel tank capacity | 81 l (21.4 US gal | 17.82 UK gal) |
| Length | 5023 mm (197.76 in.) |
| Width | 1799 mm (70.83 in.) |
| Height | 1345 mm (52.95 in.) |
| Wheelbase | 2870 mm (112.99 in.) |
| Front track | 1500 mm (59.06 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 | 255/40 R18 |
Powertrain & Engine Architecture
The heart of the XJ R is the 4.0-liter supercharged V8 engine, designated AJ26S or AJ27S depending on minor revisions. This engine is a 60-degree V8 featuring a Roots-type supercharger, providing forced induction for a substantial power boost. The engine utilizes multi-port fuel injection and a double overhead camshaft (DOHC) valvetrain with four valves per cylinder. The supercharger, driven by the engine’s crankshaft, delivers boost at relatively low engine speeds, contributing to the R’s strong mid-range acceleration. The engine’s aluminum block and heads contribute to weight savings. The XJ R exclusively used a 5-speed automatic transmission, specifically a ZF 5HP24 unit. This transmission was known for its smoothness and reliability, but its gear ratios were tuned for a balance between performance and refinement rather than outright acceleration.
Driving Characteristics
The XJ R offered a markedly different driving experience compared to other XJ variants. The supercharged V8 delivered a potent 363 horsepower and 372 lb-ft of torque, enabling a 0-60 mph time of around 5.3 seconds and a top speed electronically limited to 155 mph. The automatic transmission, while smooth, wasn’t as responsive as a manual gearbox, but it provided effortless cruising. The suspension, while retaining the XJ’s inherent comfort, was firmer and more controlled in the R model, reducing body roll during cornering. The steering was precise and well-weighted, providing good feedback to the driver. Compared to the naturally aspirated V8 models, the R offered significantly more power and acceleration, making it a true performance sedan. However, the supercharger did impact fuel economy, with combined fuel consumption averaging around 18.7 US mpg.
Equipment & Trim Levels
The XJ R came standard with a high level of equipment, befitting its flagship status. Interior features included Connolly leather upholstery, wood veneer trim, and automatic climate control. Standard safety features included ABS, traction control, and a driver’s airbag. Optional extras included a premium sound system, rear seat entertainment, and a sunroof. The R model also featured unique exterior styling cues, such as a mesh grille, body-colored side moldings, and 18-inch alloy wheels. Interior trim options were relatively limited, focusing on luxurious materials and a sophisticated aesthetic.
Chassis & Braking
The XJ R benefited from the X308’s advanced chassis construction, featuring a high percentage of aluminum components. The suspension utilized double wishbones at both the front and rear, providing a comfortable ride and good handling. Brakes were ventilated discs all around, providing ample stopping power. The R model also featured a slightly stiffer suspension setup compared to other XJ variants, improving handling and reducing body roll. ABS was standard, enhancing braking performance and stability.
Market Reception & Comparison
The XJ R was generally well-received by automotive critics, who praised its combination of luxury, performance, and refinement. It was seen as a credible alternative to German performance sedans such as the BMW 7 Series and Mercedes-Benz S-Class. However, some critics noted that the automatic transmission wasn’t as engaging as a manual gearbox, and the fuel economy was relatively poor. Compared to the standard XJ models, the R offered a significant performance upgrade, but at a higher price point. The R also tended to be more expensive to maintain due to the complexity of the supercharged engine.
Legacy
The XJ X308 R remains a desirable classic Jaguar today, appreciated for its blend of luxury and performance. The supercharged V8 engine is generally reliable, although regular maintenance is essential. The ZF automatic transmission is also known for its durability. However, like all Jaguars of this era, the XJ R can be prone to electrical issues and corrosion. Finding well-maintained examples is becoming increasingly difficult, and prices have been steadily rising in recent years. The XJ R represents a high point in Jaguar’s engineering and design, offering a unique and rewarding driving experience.
