The Jaguar XJSc Convertible 4.0, produced between 1990 and 1994, represented the final iteration of the XJ-S (XJS) model line, offering open-air motoring with the luxury and performance Jaguar was known for. This variant, powered by the 4.0-liter inline-six engine, was positioned as a premium offering within the XJS range, bridging the gap between the earlier 3.6-liter models and the later, more exclusive 6.0-liter versions. It was a key part of Jaguar’s attempt to modernize its image and appeal to a broader customer base, particularly in North America where convertibles were highly sought after. The XJSc Convertible 4.0 was built on the XJ-S platform (internally designated as XJ40), which had undergone significant revisions over its production run to improve reliability and refinement.
Technical Specifications
| Brand | Jaguar |
| Model | XJS |
| Generation | XJSc Convertible |
| Type (Engine) | 4.0 (226 Hp) |
| Start of production | 1990 |
| End of production | 1994 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Cabriolet |
| Seats | 4 |
| Doors | 2 |
| Fuel consumption (urban) | 16.7 l/100 km (14.1 US mpg, 16.9 UK mpg, 6 km/l) |
| Fuel consumption (extra urban) | 8.1 l/100 km (29 US mpg, 34.9 UK mpg, 12.3 km/l) |
| Fuel consumption (combined) | 9.9 l/100 km (23.8 US mpg, 28.5 UK mpg, 10.1 km/l) |
| Fuel Type | Petrol (Gasoline) |
| Acceleration 0 – 100 km/h | 8.2 sec |
| Acceleration 0 – 62 mph | 8.2 sec |
| Acceleration 0 – 60 mph | 7.8 sec |
| Maximum speed | 225 km/h (139.81 mph) |
| Weight-to-power ratio | 7.8 kg/Hp, 128.4 Hp/tonne |
| Weight-to-torque ratio | 4.7 kg/Nm, 214.2 Nm/tonne |
| Power | 226 Hp @ 4750 rpm |
| Power per litre | 56.8 Hp/l |
| Torque | 377 Nm @ 3650 rpm (278.06 lb.-ft. @ 3650 rpm) |
| Engine layout | Front, Longitudinal |
| Engine displacement | 3980 cm3 (242.87 cu. in.) |
| Number of cylinders | 6 |
| Engine configuration | Inline |
| Cylinder Bore | 91 mm (3.58 in.) |
| Piston Stroke | 102 mm (4.02 in.) |
| Compression ratio | 9.5:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Multi-port manifold injection |
| Engine aspiration | Naturally aspirated |
| Kerb Weight | 1760 kg (3880.14 lbs.) |
| Max. weight | 2000 kg (4409.25 lbs.) |
| Max load | 240 kg (529.11 lbs.) |
| Trunk (boot) space – minimum | 407 l (14.37 cu. ft.) |
| Fuel tank capacity | 89 l (23.51 US gal | 19.58 UK gal) |
| Length | 4820 mm (189.76 in.) |
| Width | 1793 mm (70.59 in.) |
| Height | 1279 mm (50.35 in.) |
| Wheelbase | 2588 mm (101.89 in.) |
| Front track | 1489 mm (58.62 in.) |
| Rear (Back) track | 1504 mm (59.21 in.) |
| Drivetrain Architecture | The Internal combustion engine (ICE) drives the rear wheels of the vehicle. |
| Drive wheel | Rear wheel drive |
| Number of gears and type of gearbox | 5 gears, manual transmission |
| Front suspension | Double wishbone |
| Rear suspension | Double wishbone |
| Front brakes | Ventilated discs |
| Rear brakes | Disc |
| Assisting systems | ABS (Anti-lock braking system), Hydraulic Steering |
| Tires size | 230/65 ZR16 |
Powertrain & Engine Architecture
The heart of the XJSc Convertible 4.0 was Jaguar’s 3,980cc (242.87 cu. in.) inline-six engine. This engine, internally designated as the AJ6, was a significant upgrade over the earlier 3.6-liter unit. It featured a larger bore and stroke, along with revised cylinder heads and fuel injection system. The 4.0-liter engine utilized a Bosch Motronic fuel injection system, managing fuel delivery and ignition timing for optimal performance and efficiency. The engine boasted four valves per cylinder, operated by a dual overhead camshaft design, contributing to its relatively high specific output. The five-speed manual transmission was standard, providing drivers with full control over the engine’s power. The engine’s longitudinal mounting and rear-wheel-drive configuration were hallmarks of traditional Jaguar engineering.
Driving Characteristics
The 4.0-liter engine, paired with the five-speed manual transmission, provided a noticeable improvement in performance compared to the earlier XJ-S models. Acceleration from 0 to 60 mph was achieved in around 7.8 seconds, and the car could reach a top speed of 139.81 mph. While not a sports car in the modern sense, the XJSc Convertible 4.0 offered a refined and engaging driving experience. The inline-six engine delivered smooth, linear power throughout the rev range, making it well-suited for both relaxed cruising and spirited driving. The manual transmission allowed for precise gear selection, enhancing driver involvement. Compared to the 3.6-liter models, the 4.0-liter offered more torque, resulting in improved responsiveness and easier overtaking. The suspension, while comfortable, provided adequate control in corners, although body roll was noticeable due to the car’s weight.
Equipment & Trim Levels
The XJSc Convertible 4.0 was well-equipped for its time, reflecting Jaguar’s commitment to luxury. Standard features included leather upholstery, power windows, power steering, air conditioning, and an AM/FM stereo. The interior featured wood trim and a generally elegant design. Optional extras included a premium sound system, heated seats, and a self-leveling suspension system. The convertible top was a fully automatic, lined unit, providing good insulation from the elements when raised. Trim levels were relatively limited, with most customization options available through individual selections rather than distinct packages.
Chassis & Braking
The XJSc Convertible 4.0 utilized a robust chassis based on the XJ-S platform. The suspension employed double wishbones at both the front and rear, providing a comfortable ride and reasonable handling. Ventilated disc brakes were fitted to all four wheels, offering ample stopping power. An anti-lock braking system (ABS) was standard, enhancing safety. The steering was hydraulic power-assisted, making the car easy to maneuver at low speeds. The car’s weight, approximately 3,880 lbs, contributed to its stability but also limited its agility compared to lighter sports cars.
Market Reception & Comparison
The XJSc Convertible 4.0 was generally well-received by critics, who praised its combination of luxury, performance, and open-air enjoyment. It was seen as a more desirable alternative to the earlier 3.6-liter models, offering a significant improvement in power and refinement. Compared to the later 6.0-liter versions, the 4.0-liter offered a more balanced driving experience, with less overwhelming power and slightly better fuel economy. Fuel economy, however, remained relatively poor by modern standards, averaging around 23.8 US mpg in combined driving. Reliability was generally good, although the XJ-S platform was known for its complex electrical systems, which could occasionally require attention.
Legacy
The Jaguar XJSc Convertible 4.0 remains a popular choice among classic Jaguar enthusiasts. The 4.0-liter inline-six engine is considered to be a robust and reliable unit, although regular maintenance is essential to keep it in good condition. Parts availability is generally good, although some components can be expensive. The XJSc Convertible 4.0 has appreciated in value in recent years, reflecting its desirability and rarity. It represents a significant chapter in Jaguar’s history, embodying the brand’s commitment to luxury, performance, and style. Today, well-maintained examples are highly sought after by collectors and enthusiasts alike, offering a unique and rewarding classic car experience.

