The Jaguar XJ X350, specifically the 4.2 V8 Supercharged variant, represented a significant step forward for the iconic British luxury sedan. Produced from 2004 to 2006, this iteration of the XJ aimed to blend traditional Jaguar elegance with modern technology and performance. Positioned as a high-performance offering within the X350 range, the 4.2 V8 Supercharged model delivered a substantial increase in power and refinement compared to the naturally aspirated versions. It served as a flagship model, showcasing Jaguar’s engineering capabilities and competing directly with established luxury brands like BMW and Mercedes-Benz.
Technical Specifications
| Brand | Jaguar |
| Model | XJ |
| Generation | XJ (X350) |
| Type (Engine) | 4.2 V8 32V L Super (400 Hp) Automatic |
| Start of production | 2004 |
| End of production | 2006 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Sedan |
| Seats | 5 |
| Doors | 4 |
| Fuel consumption (urban) | 18.6 l/100 km (12.6 US mpg) |
| Fuel consumption (extra urban) | 9 l/100 km (26.1 US mpg) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 5.3 sec |
| Acceleration 0 – 62 mph | 5.3 sec |
| Acceleration 0 – 60 mph | 5 sec |
| Maximum speed | 250 km/h (155.34 mph) |
| Weight-to-power ratio | 4.2 kg/Hp |
| Weight-to-torque ratio | 3.1 kg/Nm |
| Power | 400 Hp @ 6100 rpm |
| Torque | 541 Nm @ 3500 rpm (399.02 lb.-ft. @ 3500 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | AJ33S, AJ34S |
| Engine displacement | 4196 cm3 (256.06 cu. in.) |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 86 mm (3.39 in.) |
| Piston Stroke | 90.3 mm (3.56 in.) |
| Compression ratio | 9.1:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Supercharger, Intercooler |
| Engine oil capacity | 6 l (6.34 US qt | 5.28 UK qt) |
| Coolant | 9.45 l (9.99 US qt | 8.31 UK qt) |
| Kerb Weight | 1690 kg (3725.81 lbs.) |
| Max. weight | 2275 kg (5015.52 lbs.) |
| Max load | 585 kg (1289.7 lbs.) |
| Trunk (boot) space – minimum | 470 l (16.6 cu. ft.) |
| Fuel tank capacity | 85 l (22.45 US gal | 18.7 UK gal) |
| Length | 5215 mm (205.31 in.) |
| Width | 1860 mm (73.23 in.) |
| Height | 1448 mm (57.01 in.) |
| Wheelbase | 3159 mm (124.37 in.) |
| Front track | 1556 mm (61.26 in.) |
| Rear (Back) track | 1546 mm (60.87 in.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 6 gears, automatic transmission |
| Front suspension | Hydro-pneumatic element |
| Rear suspension | Hydro-pneumatic element |
| Front brakes | Ventilated discs |
| Rear brakes | Ventilated discs |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Steering rack and pinion |
| Tires size | 255/40 R19 |
Introduction
The X350 generation Jaguar XJ, launched in 2003, marked a departure from the previous XJ models with its increased use of aluminum in its construction. The 4.2 V8 Supercharged model, produced from 2004-2006, was the performance leader of the range. It built upon the XJ’s reputation for luxury and refinement, adding a significant dose of power and sporting capability. This variant was aimed at buyers who desired a high-performance luxury sedan without sacrificing the comfort and sophistication expected of a Jaguar.
Powertrain & Engine Architecture
At the heart of the XJ 4.2 V8 Supercharged lies the AJ33S/AJ34S engine, a 4.2-liter naturally aspirated V8 engine augmented by a Lysholm-type twin-screw supercharger. This engine produced 400 horsepower at 6100 rpm and 541 Nm (399 lb-ft) of torque at 3500 rpm. The engine featured multi-port fuel injection and a compression ratio of 9.1:1. The supercharger, along with an intercooler, significantly boosted low-end torque and overall power output. The engine’s architecture is a 60-degree V8, known for its smoothness and inherent balance.
The XJ 4.2 V8 Supercharged was exclusively paired with a six-speed automatic transmission, engineered by ZF. This transmission offered smooth and responsive shifts, contributing to the car’s refined driving experience. The transmission was electronically controlled, adapting shift points based on driving conditions and throttle input. While not a dual-clutch transmission, it was considered one of the best conventional automatics of its time.
Driving Characteristics
The 4.2 V8 Supercharged XJ delivered exhilarating performance. Acceleration from 0 to 60 mph was achieved in around 5 seconds, and the car could reach a top speed of 155 mph. The supercharger provided instant throttle response and a broad torque curve, making the car feel powerful and effortless in everyday driving. The six-speed automatic transmission was well-matched to the engine, providing smooth and timely shifts. Compared to the naturally aspirated 4.2-liter XJ, the supercharged version offered a dramatically different driving experience, with significantly more power and a more engaging feel. The manual transmission was not offered on this model, focusing on providing a seamless and luxurious driving experience.
Equipment & Trim Levels
The 4.2 V8 Supercharged XJ came standard with a high level of equipment, befitting its flagship status. Standard features included leather upholstery, wood veneer trim, a premium sound system, automatic climate control, and power-adjustable seats with memory function. Optional extras included a rear-seat entertainment system, upgraded leather options, and various exterior styling enhancements. The interior was designed to provide a luxurious and comfortable environment for both driver and passengers.
Chassis & Braking
The X350 XJ featured an all-aluminum chassis, a first for a mass-produced Jaguar. This lightweight construction contributed to the car’s agility and improved fuel efficiency. The suspension system utilized a sophisticated hydro-pneumatic setup, providing a smooth and comfortable ride. The front and rear brakes were ventilated discs, providing ample stopping power. Anti-lock brakes (ABS) were standard, enhancing safety and control. The car’s suspension was tuned to balance comfort and handling, offering a refined driving experience without sacrificing stability.
Market Reception & Comparison
The XJ 4.2 V8 Supercharged was generally well-received by automotive critics. It was praised for its powerful engine, luxurious interior, and refined driving experience. However, some critics noted the car’s relatively high price and complex electronics. Compared to the naturally aspirated 4.2-liter XJ, the supercharged version offered a significant performance upgrade, but at a higher cost. Fuel economy was also lower with the supercharged engine, reflecting its increased power output. Against its rivals, such as the BMW 7 Series and Mercedes-Benz S-Class, the XJ 4.2 V8 Supercharged offered a unique blend of British luxury and performance.
Legacy
The Jaguar XJ X350 4.2 V8 Supercharged remains a desirable luxury sedan in the used car market. The AJ33S/AJ34S engine is generally considered reliable, although regular maintenance is essential. The car’s all-aluminum chassis and sophisticated suspension system require specialized knowledge for repairs. Despite its age, the XJ 4.2 V8 Supercharged continues to offer a compelling combination of performance, luxury, and style, making it a popular choice for enthusiasts and collectors alike. The complex electronics can present challenges for owners, but the car’s overall build quality and engineering excellence ensure its continued appeal.
