Jaguar XJ Series 3 V12 SovereignThe Series 3 of 1979 is imbued with a similar feeling of consistency to its direct predecessor in its responses – the result of years of development of the basic design – and it’s an interesting blend of old and new thinking. Inside there’s a smaller, more modern steering wheel with a leather-bound rim that is thicker than before but still very slim by contemporary standards. As in the earlier cars the wheel is offset slightly to the left, though not enough to make much difference to the driving position. The steering itself is just a fraction weightier than before, but still disconcertingly light thanks to substantial power assistance. An old-fashioned umbrella handle handbrake still hides under the dashboard, ready to clout your left knee if you leap aboard unawares.
The all-disc brakes – inboard at the back, as on all these cars – are strong and with ventilated rotors at the front they should prove to be fade-free, which matters when you have almost 300bhp under your right foot from the fuel-injected V12 engine. It’s an extraordinary motor, rightly renowned throughout the Seventies as one of the best engines anywhere on the planet. The early carburettor version fitted to the Series 1 that was fed by four Zenith-Strombergs could be troublesome, but fitting Lucas fuel injection in the mid-Seventies made the V12 a more dependable engine and in 1981 revisions to the cylinder heads and pistons in the High Efficiency version made major improvements to fuel economy without compromising outright power. This is the engine fitted in Paul Upton’s 1987 V12 Sovereign, and compared to the six-cylinder motors it delivers an extra level of silky smoothness to the way the XJ drives.
’The V12 will sprint to 60mph in just over eight seconds, fast enough to embarrass some Eighties sports cars’
The engine is never felt, and almost never heard. At idle the only aural indication that it is running is a gentle whine from the fuel pumps, and even when the accelerator is pushed to the carpet and the Series 3 is propelled to the horizon with never-ending acceleration there’s barely more than a murmur from the engine. From rest the Sovereign will sprint to 60mph in a fraction over eight seconds, enough to embarrass some Eighties sports cars, and it would be even quicker if the automatic transmission, now a GM400 unit in place of the earlier Borg-Warner, had more than three ratios as most competitors now did.
But the Sovereign will cruise all day at 80mph in top with the 5.3-litre engine loping along at only 3000rpm or so, and extra pace for overtaking is just a flex of your right toe away. It’s at these speeds that the performance advantage of the V12 over the six-cylinder engines becomes apparent. The only downside is the V12’s ability to drink unleaded, though these later engines demand refuelling stops far less often than the earlier ones.
Even now this is a car that could cross a continent in a day, with the compliant suspension delivering high-speed stability and almost unmatched comfort. Motorways – or more accurately autobahns – are its natural habitat, but the V12 Sovereign still tackles twisty roads with aplomb. The Jaguar flows through a series of turns with a lack of fuss that few rivals could match, even as the XJ’s basic design neared its 20th birthday.
The comprehensive revisions that had kept the Series 3 fresh also included more modern bumpers and flush-fitting door handles, and Italian design house Pininfarina subtly reshaped the top half of the car. The windscreen was more heavily raked, the rear pillars were wider and more upright, and the roof was narrower but extended a few inches further back to improve headroom for rear seat occupants.
But the basic age of the design was betrayed by the closeness of the windscreen to the wheel, the narrow cabin that limited space for shoulders and elbows, and leg room which was still at a premium despite the overall length growing to 195in, putting it between a Mercedes-Benz E-class and S-class in size.
The 3.4-litre and 4.2-litre XK sixes were both now fitted with fuel-injection and were available until 1987, when the six-cylinder cars were replaced by the XJ40-generation XJ6 powered by the new AJ6 engine. But the engine bay of the XJ40 was too narrow for the V12 to fit easily – some say it was engineered that way deliberately so no BL bean counter could insist Jaguar installed a Rover V8 in place of its own in-line sixes – and so the old car was kept in production in V12 form right up to 1992.
By then Sir John Egan’s efforts as chief executive had raised Jaguar quality to levels the brand had never before achieved, and the company had been hived off from what remained of British Leyland to operate as an independent before Ford added it to a growing collection of premium automotive brands.
All the XJs are attractive, usable classics offering plenty of comfort and refinement. The Series 1 cars, at the time seen very much as the cutting edge of Jaguar innovation, now represent a characterful halfway house between the old-school Jaguars of the Sixties and the modern classic XJs and XJ-S of the Seventies.
The Series 2s offer a more cohesive driving experience, but saloons in good, standard condition are becoming scarce and the coupés, which were always rare, are now starting to fetch the kind of prices that reflect their exclusivity.
The Series 3 appeals to a slightly different kind of buyer, one who wants classic Jaguar looks but appreciates the improved quality and reliability of a car that had been in constant development for well over two decades by the time the last XJs were built in 1992.
Those final cars were all V12s, and the biggest of the XJ engines appeals for its supreme refinement and high-speed cruising ability, if not for the thirst of its pre-HE iterations. As the fine coupé in our group demonstrates, the 4.2-litre is the best all-rounder, with near enough as much performance in everyday motoring as the V12 but lower running costs. The elegance of the pillarless body just adds to the XJ’s appeal. It’s an easy decision.
Thanks to: Keith Parrington of XJ-Restorations (xjrestorations.co.uk), Robert Hughes (roberthughes.co.uk) and Jaguar Drivers’ Club XJ registrar Steve Swinscoe
Paul Upton on his Series 3 V12
‘My father has a 1992 Series 3 and when he brought it round to my house I quickly got the idea in my head that I wanted to get one. I bought this one from Jaguar specialist Robert Hughes about a year ago.
‘Everything works on it – sunroof, cruise control, aircon. I’ve done about 1200 miles in it and nothing has gone wrong. It starts every morning. When it’s cold it just starts straight on the button, but, notoriously, hot starting is worse. This is a pre-cat car which I understand is better if you have a problem, because you can’t get the cats. ‘The pre-fuel injection V12s give you about 10-12mpg, so this is quite good at 20mpg. It’s not a fast car but you do progress. It’s designed to be quiet – sometimes you wonder if it’s switched on. I’m biased but I think it’s a very pretty car – they’d got it right by this stage.
‘You can pay £15,000 for a very low mileage one. I’ve got this insured for £12,000 and that’s a lot of classic for the money. I won’t lose on it. They’re not quite classic cars yet, in some people’s minds, especially the Series 3. But their time will come.’
TECHNICAL DATA FILE SPECIFICATIONS Jaguar Sovereign V12
As Series 1 except Engine 5344cc V12, sohc per bank, 24-valve, Lucas fuel injection
Power and torque 299bhp @ 5500rpm; 318lb ft @ 3000rpm / DIN
Transmission GM three-speed automatic
Weight 1900kg (4189lb)
Performance Top speed: 140mph; 0-60mph: 8.2sec
Classic Cars Price Guide £5,000-£15,000