Jaguar XJ6, Full Specifications
Overview
| Spec | Value |
|---|---|
| Production Years | 1968-1992 |
| Body Styles | 4-door saloon (standard wheelbase and long wheelbase) |
| Engine(s) | 2.8L XK I6, 4.2L XK I6, 5.3L V12 |
| Displacement | 2792cc (2.8), 4235cc (4.2), 5343cc (V12) |
| Power | 140-285 bhp (depending on variant) |
| Torque | 170-294 lb-ft (depending on variant) |
| Transmission | 4-speed manual with overdrive, 3-speed automatic (BW66 or GM TH400), 4-speed automatic (ZF, late cars) |
| Drive | Rear-wheel drive |
| Suspension (front) | Independent, double wishbones, coil springs, anti-roll bar, telescopic dampers |
| Suspension (rear) | Independent, lower wishbones, fixed-length driveshafts, coil springs, anti-roll bar |
| Brakes | Disc brakes all round, servo-assisted |
| Steering | Rack and pinion, power-assisted (standard on most models) |
| Construction | Steel monocoque with bolt-on subframes |
Series 1, 2.8L (1968-1973)
| Spec | Value |
|---|---|
| Engine | 2.8L XK DOHC inline-6 |
| Displacement | 2792cc |
| Bore x Stroke | 83mm x 86mm |
| Compression Ratio | 9.0:1 |
| Fuel System | 2x SU HD6 carburettors |
| Power | 140 bhp @ 5500 rpm |
| Torque | 170 lb-ft (230 Nm) @ 3750 rpm |
| Transmission | 4-speed manual with overdrive or 3-speed BW66 automatic |
| 0-100 km/h | ~11.5 seconds |
| Top Speed | 185 km/h (115 mph) |
| Fuel Economy | 14-18 L/100km |
| Kerb Weight | 1610 kg |
| Length | 4899mm (SWB), 4999mm (LWB) |
| Width | 1770mm |
| Height | 1359mm |
| Wheelbase | 2762mm (SWB), 2862mm (LWB) |
| Track (front/rear) | 1461mm / 1461mm |
| Fuel Tank | 82 litres |
| Tyres | 205/70 VR 15 (E70 VR 15) |
Note: The 2.8-litre is generally considered the least desirable XJ6 variant. Underpowered, rough-running, and prone to bottom-end problems. The 4.2 is the engine to have.
Series 1, 4.2L (1968-1973)
| Spec | Value |
|---|---|
| Engine | 4.2L XK DOHC inline-6 |
| Displacement | 4235cc |
| Bore x Stroke | 92.07mm x 106mm |
| Compression Ratio | 9.0:1 (8.0:1 low compression option) |
| Fuel System | 2x SU HD8 carburettors |
| Power | 170 bhp @ 4500 rpm (net) |
| Torque | 238 lb-ft (323 Nm) @ 3000 rpm |
| Transmission | 4-speed manual with overdrive or 3-speed BW66 automatic |
| 0-100 km/h | ~8.5 seconds |
| Top Speed | 195 km/h (121 mph) |
| Fuel Economy | 14-18 L/100km |
| Kerb Weight | 1660 kg (SWB), 1700 kg (LWB) |
| Length | 4899mm (SWB), 4999mm (LWB) |
| Width | 1770mm |
| Height | 1359mm |
| Wheelbase | 2762mm (SWB), 2862mm (LWB) |
| Track (front/rear) | 1461mm / 1461mm |
| Fuel Tank | 82 litres |
| Tyres | 205/70 VR 15 (E70 VR 15) |
Series 1, V12 / XJ12 (1972-1973)
| Spec | Value |
|---|---|
| Engine | 5.3L SOHC V12 |
| Displacement | 5343cc |
| Bore x Stroke | 90mm x 70mm |
| Compression Ratio | 9.0:1 |
| Fuel System | Lucas/Bosch fuel injection |
| Power | 285 bhp @ 5500 rpm |
| Torque | 294 lb-ft (399 Nm) @ 3500 rpm |
| Transmission | 3-speed BW66 automatic (standard) |
| 0-100 km/h | ~7.5 seconds |
| Top Speed | 225 km/h (140 mph) |
| Fuel Economy | 20-26 L/100km |
| Kerb Weight | 1800 kg |
| Length | 4899mm (SWB), 4999mm (LWB) |
| Width | 1770mm |
| Height | 1359mm |
| Wheelbase | 2762mm (SWB), 2862mm (LWB) |
| Track (front/rear) | 1461mm / 1461mm |
| Fuel Tank | 82 litres |
| Tyres | 205/70 VR 15 (E70 VR 15) |
Series 2, 4.2L (1973-1979)
| Spec | Value |
|---|---|
| Engine | 4.2L XK DOHC inline-6 |
| Displacement | 4235cc |
| Bore x Stroke | 92.07mm x 106mm |
| Compression Ratio | 8.0:1 (some markets), 9.0:1 |
| Fuel System | 2x SU HIF7 carburettors (early) or Lucas fuel injection (later) |
| Power | 170 bhp @ 4500 rpm (carb), 162 bhp (injected, some markets) |
| Torque | 238 lb-ft (323 Nm) @ 3000 rpm |
| Transmission | 3-speed BW66 automatic or GM TH400 automatic (later), manual rare |
| 0-100 km/h | ~9.0 seconds |
| Top Speed | 190 km/h (118 mph) |
| Fuel Economy | 14-19 L/100km |
| Kerb Weight | 1710 kg (SWB), 1750 kg (LWB) |
| Length | 4950mm (SWB), 5050mm (LWB) |
| Width | 1770mm |
| Height | 1370mm |
| Wheelbase | 2762mm (SWB), 2862mm (LWB) |
| Track (front/rear) | 1461mm / 1461mm |
| Fuel Tank | 82 litres |
| Tyres | 205/70 VR 15 |
Key Series 2 Changes
- Raised rubber-faced bumpers (US safety compliance)
- Enlarged grille
- Modified interior (safety regulations)
- Revised instrumentation
- Improved heating and ventilation
- Fuel injection on some markets
- GM TH400 automatic on later cars (replacing BW66)
Series 2, V12 / XJ12 (1973-1979)
| Spec | Value |
|---|---|
| Engine | 5.3L SOHC V12 |
| Displacement | 5343cc |
| Bore x Stroke | 90mm x 70mm |
| Compression Ratio | 9.0:1 (7.8:1 US-spec) |
| Fuel System | Lucas/Bosch fuel injection |
| Power | 285 bhp @ 5500 rpm (Euro), 244 bhp (US) |
| Torque | 294 lb-ft (399 Nm) @ 3500 rpm |
| Transmission | 3-speed BW66 or GM TH400 automatic |
| 0-100 km/h | ~7.8 seconds |
| Top Speed | 225 km/h (140 mph) |
| Fuel Economy | 20-26 L/100km |
| Kerb Weight | 1870 kg |
| Length | 4950mm (SWB), 5050mm (LWB) |
| Width | 1770mm |
| Height | 1370mm |
| Wheelbase | 2762mm (SWB), 2862mm (LWB) |
| Fuel Tank | 82 litres |
| Tyres | 205/70 VR 15 |
Series 3, 4.2L (1979-1992)
| Spec | Value |
|---|---|
| Engine | 4.2L XK DOHC inline-6 |
| Displacement | 4235cc |
| Bore x Stroke | 92.07mm x 106mm |
| Compression Ratio | 8.1:1 |
| Fuel System | Lucas fuel injection (early) or Bosch fuel injection (later) |
| Power | 163 bhp @ 4750 rpm |
| Torque | 232 lb-ft (315 Nm) @ 2500 rpm |
| Transmission | 3-speed GM TH400 automatic (standard), 4-speed ZF automatic (late cars), manual very rare |
| 0-100 km/h | ~9.5 seconds |
| Top Speed | 195 km/h (121 mph) |
| Fuel Economy | 14-18 L/100km |
| Kerb Weight | 1740 kg (SWB), 1790 kg (LWB) |
| Length | 4967mm (SWB), 5067mm (LWB) |
| Width | 1770mm |
| Height | 1378mm |
| Wheelbase | 2762mm (SWB), 2862mm (LWB) |
| Track (front/rear) | 1485mm / 1485mm |
| Fuel Tank | 82 litres |
| Tyres | 205/70 VR 15 (early), 215/70 VR 15 (later) |
Key Series 3 Changes
- Pininfarina styling revisions (raised roofline, flush door handles, revised bumpers)
- Improved build quality throughout production
- Switch from Lucas to Bosch ignition (mid-production, significant reliability improvement)
- GM TH400 automatic standard
- Improved corrosion protection
- Sovereign trim level (extensive standard equipment)
- Revised instrumentation and switchgear
Series 3, V12 HE / XJ12 (1981-1992)
| Spec | Value |
|---|---|
| Engine | 5.3L SOHC V12 HE (High Efficiency) |
| Displacement | 5343cc |
| Bore x Stroke | 90mm x 70mm |
| Compression Ratio | 12.5:1 |
| Fuel System | Lucas digital fuel injection |
| Power | 299 bhp @ 5500 rpm |
| Torque | 318 lb-ft (431 Nm) @ 3000 rpm |
| Transmission | 3-speed GM TH400 automatic |
| 0-100 km/h | ~7.5 seconds |
| Top Speed | 238 km/h (148 mph) |
| Fuel Economy | 16-22 L/100km |
| Kerb Weight | 1870 kg |
| Length | 5067mm (LWB only) |
| Width | 1770mm |
| Height | 1378mm |
| Wheelbase | 2862mm (LWB only) |
| Track (front/rear) | 1485mm / 1485mm |
| Fuel Tank | 82 litres |
| Tyres | 215/70 VR 15 |
Note: The Series 3 V12 was offered only in long wheelbase form. Badged as XJ12, Sovereign V12, or Daimler Double Six depending on trim level.
Engine Variants
2.8L XK DOHC Inline-6
A de-stroked version of the 4.2, offered as a budget entry point on Series 1 and early Series 2 cars. Reduced capacity created balance issues and increased stress on the bottom end. Underpowered in the heavy XJ body. The 2.8 is universally considered the weakest XJ6 engine option and best avoided. Many have been replaced with 4.2 units over the years.
4.2L XK DOHC Inline-6
The definitive XJ6 engine. The XK twin-cam six in its most developed road-going form. Not the most powerful version (the E-Type tune made more horsepower), but optimised for low-speed torque and smooth power delivery that suited the XJ6’s touring character. The 4.2 is flexible, refined, and long-lived, 200,000+ km is routine with proper maintenance. Oil leaks are endemic but manageable. Carburetted cars (Series 1, early Series 2) are simpler but need regular tuning. Fuel-injected cars (late Series 2, all Series 3) are more refined but have their own diagnostic challenges.
5.3L SOHC V12
The same V12 as the E-Type Series 3 and XJ-S. In XJ6 application, it creates the smoothest luxury saloon available at any price. Pre-HE versions (1972-1981) are spectacularly thirsty. The HE version (1981 onwards) is more practical while retaining all the mechanical refinement. The V12 requires meticulous cooling system maintenance and more frequent attention to ignition components. Running costs are 40-60% higher than the six-cylinder.
Transmission Options
4-speed manual with overdrive
Offered on six-cylinder cars only. Rare, particularly in Australia. Adds driver engagement but the XJ6’s character suits the automatic better. The manual gearbox itself is robust. Overdrive is electrically engaged and works on third and fourth gears.
Borg-Warner BW66, 3-speed automatic (early cars)
The original automatic. Adequate but unreliable by modern standards. The BW66 copes with the six-cylinder but struggles with the V12’s torque. Many have been replaced with GM TH400 units. If the car still has a BW66, budget for a potential conversion.
GM Turbo-Hydramatic 400 (TH400), 3-speed automatic
The standard automatic on later Series 2 and all Series 3 models. Virtually indestructible, same unit used in American trucks and rated for far more torque than any XJ6 engine produces. Smooth, strong, reliable. Change the fluid every 40,000 km and it’ll outlast the car.
ZF 4-speed automatic (very late Series 3)
Fitted to the final production Series 3 models. Adds a fourth ratio for improved cruising refinement and economy. Less common than the TH400 but equally reliable.
Trim Levels and Badges
| Badge | Description |
|---|---|
| Jaguar XJ6 | Standard six-cylinder model. Well-equipped but not fully loaded. |
| Jaguar Sovereign | Premium six-cylinder. Full leather, wood, electric seats, comprehensive equipment. |
| Jaguar XJ12 | V12 engine, Jaguar grille. |
| Jaguar Sovereign V12 | V12 with Sovereign luxury trim. |
| Daimler Sovereign | Six-cylinder with Daimler fluted grille, higher trim. |
| Daimler Double Six | V12 with Daimler badge. Top of the range. |
| Daimler Vanden Plas | Highest luxury specification (some markets). Extended equipment list. |
All variants share the same basic structure, suspension, and running gear. The differences are trim, badges, and equipment levels. Daimler-badged cars command modest premiums but are mechanically identical to their Jaguar equivalents.
Production Numbers (approximate)
| Variant | Numbers Built |
|---|---|
| Series 1 (all, including XJ12) | ~83,000 |
| Series 2 (all, including XJ12) | ~91,000 |
| Series 3 (all, including XJ12) | ~132,000 |
| Total (all variants) | ~306,000 |
The XJ6 was Jaguar’s most commercially successful model, with the Series 3 accounting for the largest production run due to its 13-year lifespan.
Notable Features
- Ride quality: The XJ6’s defining characteristic. The combination of sophisticated independent suspension, carefully tuned damping, and compliant bushes created a ride that embarrassed Mercedes-Benz and BMW. Nothing else in the price range came close. Even today, a well-sorted XJ6 rides better than many modern luxury cars.
- Independent rear suspension: Derived from the E-Type system, lower wishbones, fixed-length driveshafts as upper links, coil springs, and an anti-roll bar. Complex but effective. The same basic design was used across the entire Jaguar range.
- XK engine lineage: The 4.2-litre XK six is one of the longest-serving and most celebrated engines in automotive history. Designed in the 1940s, race-proven at Le Mans, and refined across four decades of production.
- William Lyons’s final design: The XJ6 was the last car personally styled by Sir William Lyons, Jaguar’s founder. It’s arguably his finest work, a car that combined elegance, proportion, and visual drama more successfully than anything else in the luxury saloon market.
- Dual-badge strategy: The practice of selling the same car under both Jaguar and Daimler badges maximised market coverage with minimal additional investment. It continued a tradition dating back to Jaguar’s acquisition of Daimler in 1960.
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