Jaguar XJ12

Road test

Extremely high performance and luxurious running from the Coventry-built £3,800 Saloon

Last year I had a brief flirtation with the new Daimler Double-Six and more recently I have been able to gain greater experience of the same-specification Jaguar XJ12. The impression which persists is that the twelve-cylinder saloon from Coventry is quite outstanding and most certainly in the best Sir William Lyons tradition of offering such stupendous value-for-money as to drive the opposition out of the market place. The basic price of this Jaguar is £3,082. VAT, delivery charges inclusive of number plates and a year's road tax, and the extras on the test car, which consisted of laminated screen, electric window-lifts, a radio with speakers in the four doors and an automatic aerial, increase to a total of £3,883.77.

This is a very modest sum to pay for a low, handsome, fully-equipped, top-luxury car which can exceed 145 m.p.h., out-accelerate most of the world's great sports and GT cars, yet which provides comfort in the best West End club idiom, exceptionally quiet-running, and which is more than adequately shod with those Dunlop SP tyres developed specially for it and retarded with efficient servo-ventilated disc brakes. Admittedly the 5.4-litre 60-deg. V12 is a thirsty engine but those who are forming long queues for this fine new car are unlikely to worry about petrol bills, which the low purchase price of the XJ12 does to some extent offset.

The steel body shell is that of the well established XJ6 Jaguar. That is to say, without being a state-occasion limousine it provides ample space for four or five occupants while their mobile possessions can be easily loaded into the shallow 17 cu. ft. boot-space, the spare wheel being below the floor and the boot-lid closing nicely, although the key is a bit furnbly if it has to be locked.

The usual Jaguar high-grade, real leather upholstery, polished walnut facia and door-cappings, deep-pile nylon carpets, and arrangement of controls, are retained, together with knob-controlled front 1/4-lights. All these "olde-worlde" fittings contribute to a very special kind of motoring. The thin, slippery-rimmed steering wheel is small (15 in.) adjustable for column length and has a half-hornring, sounding twin horns. A 160-m.p.h. speedometer and matching tachometer are in front of the driver, their needles moving together (and swiftly!) in the same plane (when in top gear) over the white digits, in the manner we found so satisfying in pre-war Bentleys.

The central row of switches is still used, which can be confusing, although they are clearly labelled, and lit. From l. to r. these control the hazard warning, map or interior lamps, two-degrees of panel lighting, side and headlamps, two-speed wipers, electric washers, two-speed heater fan, and the fuel tanks change-over. The lamps switches are boxed together in the centre and interlocked but the separation of wipers and washers buttons is certainly inconvenient. A r.h. stalk simply looks after turn-indicating and lamps flashing and is too far below the wheel if this is set high.

Other typical Jaguar items are the vanity mirror which slides up when the wooden lid of the small lockable glove-cubby is opened, the twin petrol tanks, felt head-lining, the hand-brake-on/brake fluid low warning light (surely pioneered by Jaguar?), and the five small dials lined up centrally for oil, heat, battery, time and fuel contents readings. The hand-brake is an under-facia twist-and-turn affair. The major warning lights are clustered between the two large dials. All the controls are well placed, even if the switches are fumbly. The central console has the toggle gear lever for selecting P,R,N,D, 1 and 2 positions protruding from a nylon-brushed gate which is unsuited to rapid upward changes, because no gate protects D from N.

On the console floor are cigar-lighter and twin-lidded ash-trays and change-over for the radio speakers, the four window-lift controls are on its rear face (there are additional ones in the rear doors for back-scat passengers to use) and its front wall contains the radio and the air and heater controls with an eight-position hot-air setting. The facia has eyeball air vents, there are lever-controlled scuttle air intakes and swivelling grilles on the screen sill; the body is vented. There is a central open stowage bin, bins in the back doors and under facia shelves for oddments, also a lidded well between the front seats. The electric windows work quickly and quietly, but only if the ignition-key is used. A Triplex Hotline rear window is standardised and the test car had four Lucas headlamps and Kangol reel-type safety belts.

Performance

The performance of this XJ12 Jaguar is quite exceptional. It will exceed 145 m.p.h., accelerate to 60 m.p.h. in less than 7-1/2 sec, to 70 m.p.h. in just over 9 sec., and cover a standing-start in well under 17 sec. In the rather low 3.31-to-1 top gear the twelve-cylinder Jaguar is quicker from 40 to 60 m.p.h., the overtaking area, than a Maserati Bora or a Rolls-Royce Silver Shadow. Equally or even more impressive is the response from 100 m.p.h. when so many cars are running out of breath–the Jaguar is up to 120 m.p.h. in a matter of 12 sec. In the gear holds it will run up to better than 60 and 100 m.p,h. At the opposite extreme the engine is running at less than 3,000 r.p.m. at 70 m.p.h. in D. This is quite phenomenal performance from a comfortable 9 ft. 8 in. wheelbase saloon with a kerb weight of 35 cwt.

The engine develops peak power, 309 gross b.h.p., at 3,250 r.p.m. but has another 250 r.p.m. in hand. It consumes 99-octane fuel, having a 9.0 to 1 c.r. It is an engineering masterpiece which has been fully described in Motor Sport and which was the subject of a learned paper read before the IME by Harry Mundy, C.Eng., FIME in 1971. When cold the starter churns away for a while and nothing will happen unless the choke lever beneath the scuttle is used to enrich the four Stromberg carburetters. For a mile or so choke has to be kept on, if the engine is not to snuff out; there is a small warning light for this archaic manual service.

To me, a big vee-twelve engine should be either full of exciting urge accompanied by life's better motoring noises or else absolutely unobtrusive, as in the original Daimler Double-Six 50 of four-and-a-half decades ago. Consequently I was disappointed to find the Jaguar's power pack rocking the car slightly as it idled at 700 r.p.m. in N, or at one-and-a-half r.p.m. less in D. However, once it is opened-up it is turbine smooth and so quiet that in normal running the ticking of the Kienzle clock is audible— truly!

It is this quiet effortless running and the truly impressive pick-up which makes the XJ12 such a fatigue-free car to drive. I first got into it at the office on a day when I had arisen at 6.30 a.m., driven to London in a lesser breed of automobile, attended a lunchtime meeting, and done some office work. The Jaguar then took me home to Wales through the crush of the A40 traffic which still persists at 7 p.m. Without calling on anything like the full extent of its remarkable performance and with a pause for petrol, I was well beyond Cross Gates in 3-3/4 hours as fresh as when I set out.

At first I found the very light power steering extremely disconcerting and I think that Jaguar may well follow Rolls-Royce in making it less sensitive. As it is, you aim the car most of the time and oversteer to correct understeer. The gearing is high, at just over three turns lock-to-lock, but this lack of steering feel is quite the least endearing aspect of the XJ12. There is, however, gentle castor return action. The brakes call for quite heavy pressure and while I am aware that women can do more with their legs than with their wrists, this does not seem in keeping with the very light steering which is presumably provided for their benefit; it also spoils progressive braking. The coil-spring all-independent suspension gives a good ride, unless exceptionally bad undulations cause a kick-up or promote lurching, and road-holding, with those special Dunlop 15 in. 205/70VR tyres and a PowerLok limited-slip differential to kill wheelspin with a yelp from the back wheels, is outstanding. Up to 60 m.p.h. the running is near silent, road noise splendidly subdued except for the wheels thudding into bad road holes, the engine unheard, and wind roar not yet apparent.

It is difficult to know which is the best habitat for this latest Jaguar. Motorways are to be avoided in this sector of Europe in case the car's easy 100 m.p.h. gait earns an endorsement. The vague steering spoils the pleasure of driving the XJ12 fast on winding roads. I suppose unrestricted continental autoroutes are the best place to enjoy this kind of motoring, except that the twin ten-gallon tanks, with their lockable filler caps and splash guards in the filler necks, will be empty in less than 200 miles, which could be so tedious. The Jaguar really is very thirsty. In normal driving it gave 12.1 m.p.g. but press it hard and the consumption rises alarmingly, so that the owner can be pictured with his Barclay Card at the ready in his breast pocket . . .

At night the Lucas lamps are dipped with a foot control, which is old-fashioned but acceptable with two-pedal control, unless you are an American citizen with a foot poised over both pedals. The Borg-Warner 12 gearbox works as well as any of its kind, which means jerks on occasions. It whines very slightly and impressive as the step-off is, there is the usual disconcerting lag on kickdown, nor can bottom gear be engaged with the lever below 20 m.p.h. or be kicked-into below 30 m.p.h.

Once on the move, though, other traffic tends to vanish in the anti-dazzle rear-view mirror, unless any of the hotter BMWs are about, and they cost a mint more money in this country. They have, of course, much nicer power steering; a pity the Jaguar action is so indefinite, because the rack-and-pinion is free from lost motion. The Jaguar also has a poor turning circle. There were a few rattles on bad surfacees from the empty passenger's front seat and the doors, which have child-proof rear locks, shut indifferently. The rear passengers have their own heater control, and eyeball vent. The accelerator is a treadle and the brake pedal is reasonably large. Beneath the easily-opened, rear-hinged bonnet the long sump and transmission dipsticks in tubes, and the Lucas Pacemaker battery (with its own cooling fan) are fully accessible. The Lucas Opus ignition system obviates a distributor and a special plug spanner is provided. The instruments are all very easy to read but the fuel gauge is slow-reading and pessimistic. The illuminated switches seem to be responsible for heating the lip of the central stowage bin at night, and the wiper blades rasped on the screen and didn't self-park flush with the sill.

The engine is rather a reluctant starter from cold. The oil level showed zero after 900 miles but a quart of Castrol GTX restored it. The eared filler cap on the n/s cam box is uncornfortably close to hose-clips and when removed its washer vanished into the machinery. There was sometimes a smell of hot rubber outside the car—warm brakes? Servicing is called for every 3,000 miles. Because of its extremely high performance it is impossible not to think of the XJ12 as a Sports saloon, whereas so many of the customers will never use its absolute top pace, buying it instead for its effortless acceleration and quiet running. The luxury provided, the prestige of the vee-twelve transistorised-ignition power-unit, alone represent quite unique value-for-money and put the XJ12 among the top cars anywhere in the world. Externally the V12 is recognised by "XJ12" on the back panel, the V Twelve badge and the cranked twin exhaust tail-pipes. While I was sampling the Jaguar in this country a colleague was driving a Daimler Double-Six fast between Dover and Dijon, using, he tells me, the equivalent of £60-worth of petrol in a couple of days. His comments follow, to supplement my own findings about these distinguished new Coventry products.—W.B.

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At the same time that W.B. was driving to Wales in the Jaguar V12, I was able to drive a road test Daimler Double Six over the same route that W.B. and I took in the BMW 3.0 SCL last November (see Ten Capitals in Four Days, January 1973).

With the road still clear of holiday mimsers the V12 engine was kept thrashing at as near peak revs as felt safe. The trip included the mileage from Calais to Paris (periphique) to be 26 miles, the same as shown in the BMW. So as the speedometer was kept at between 130-140 m.p.h. with the occasional burst up to 150 m.p.h., the trip time should have been less than the BMW's 1 hr. 45 min. including a 4-min. fuel stop. However, the time taken this time was 2 hr. 15 min. including an 8-min. stop for fuel and snacks. The only explanation would seem to be the light steering which made the car feel as though several feet were needed when passing lorries at about twice their best speed, instead of the inches the BMW's more positive steering required. The fuel consumption for the 414 miles from Calais to Dijon worked out at 9.37 miles per gallon with one section dropping to 8.5 miles per gallon. The trip took 4-3/4 hours including fuel and coffee stops, an overall average of 87.1 m.p.h.

The return journey in pouring rain and heavy traffic took 5-3/4 hours which without being over-critical is not bad for a large moderately-priced saloon.—M.J.T.