The Jaguar XJ-S
High-Performance Perfection — and its British!
Jaguar is a great name of a car, with a fine racing record, and from the introduction of the svelte XK120, some would go further back, to the pre-war SS90 and SS100 sports cars, Sir William Lyons, FRSA, RDI, DTech., has been responsible for many of the best-looking and most effective British sports-cars of all time. The C-type and D-type carved a great niche in racing for Jaguar and then came the fabulous E-type that could be bought in the ordinary way of business by ordinary drivers, a true and very handsome sports-car that was as docile as it was fast and accelerative. The Jaguar V12-cylinder S-series coupe carries on admirably the tradition built up by the E-type. I simply cannot understand why more people do not acquire them, instead of buying foreign “road-burners”, because the XJ-S is a very good car indeed, in almost every respect.
This XJ-S Jaguar was introduced in April 1975, and it used much of the mechanics and build of the XJ-12 saloons, which are regarded by many as the best, and certainly the most hushed, cars in the World, and with price taken into consideration there can be few arguments against! In its early form the splendid V12 5.4-litre Jaguar engine, with one camshaft above each bank of cylinders, developed 272 (DIN) b.h.p. at 5,850 r.p.m., but recent modifications to produce improved fuel-economy (never the Jaguar V12’s strong point) have also increased the power output, to 300 (DIN) b.h.p. at 5,400 r.p.m., maximum torque now representing 318 lb./ft. at 3,900 r.p.m.
The light-alloy (block and head) power-unit that packs any Jaguar bonnet so impressively has a bore and stroke of 90 x 70 mm., giving a capacity of 5,343 c.c., or 325.8 cu. in. The two o.h.-camshafts are chain-driven. The compression-ratio is 10.0 to 1 and ignition is by Lucas Opus electronic apparatus, firing Champion N10Y sparking plugs through a magnetic-impulse distributor, in the cylinder sequence 1a, 6b, 5a, 2b, 3a, 4b, 6a, 1b, 2a, 5b, 4a, 3b. The Lucas fuel-injection feeds two six-branch light-alloy inlet manifolds, with automation of the cold-start injector. The crankshaft runs in seven plain bearings. The valve-gear incorporates inverted-bucket-tappets, with a valve-lift of 0.375″, the timing being: inlet opens 13 deg. BTDC, closes 55 deg. ATDC, exhaust opens 55 deg. BBDC, closes 13 deg. ATDC.
The open-deck cylinder blocks are of NM25 aluminium-alloy, the cylinder heads of LM25 WP, the three-plane crankshaft is of tuftrided manganese molybdenum-steel, and the base of the engine is closed with a pressed-steel sump. Fuel recirculated to the injection system by a Lucas pump and cooling is aided by belt-driven impeller feeding a Marston Superpak crossflow radiator, temperature being controlled by two thermostats opening at 88 deg. C. Also helping to keep the big engine cool are two fans, one with eleven nylon blades and a viscous coupling drive, the other having four blades and being electrically-controlled.
A three-speed General Motors Type-400 automatic gearbox is now used, replacing the former Borg-Warner automatic gearbox, also superseding the former manual-gearbox. The final-drive ratio is 3.07 to 1. Suspension is by double wishbones, coil springs and an anti-roll bar at the front, and at the front there is independent springing by lower wishbones, with the constant-length drive-shafts acting as the upper links, location being by radius-arms, and damping by twin coil-spring units on each side. Steering is by Adwest power-assistance to the rack-and-pinion gear, using a Saginaw rotary-vane pump, and braking by discs all round, those at the rear mounted inboard. Alloy 6J x 15 GKN Kent road-wheels carry 205/70 VR 15 tyres, Dunlop tubeless SP Super Sport on the test car. The XJ-S has a wheelbase of 8′ 6″ and it is 15′ 11″ long. The body is a 2 + 2 two-door steel monocoque.
Those are the technical bones of a motor-car that is a sheer pleasure to drive, gently or in pursuit of skilled enjoyment and high average-speeds. As I remembered from my first taste of a Jaguar E-type, the XJ-S is surprisingly docile to take away through heavy mid-day London traffic congestion, and it also felt nicely compact from within, belying its outward bulk. Yet as soon as the open road beckons, as they used to put it, there is that so-enjoyable, and safely-usable, very considerable performance, which, in spite of a rather protracted stop for fuel near Oxford, enabled me to knock about half-an-hour off my usual home-going journey time to Wales without feeling that I had extended the car in any way. The outstanding impression must be the very acceptable quietness and smoothness of the V12 power unit. Since the universal use of flexible engine-mountings, many engines, even some with only four cylinders, are quite smooth-running, and normally I am very content with the soothing acceleration of the V8 Rover. But the case of the V12 Jaguar, such smooth unobtrusiveness is maintained right up the scale, to well beyond 100 m.p.h. for instance. The XJ-S is, indeed, a motor-car in which even those who are anxious to observe the requirements of the Law, if only to preserve their clean driving-licences, will find that 100 m.p.h. and more comes up almost unnoticed, and not only on Motorways. Conversely, at an idling speed of 700 r.p.m. this Jaguar engine is quite inaudible to the car’s occupants, although it does very slightly “rock-the-boat”.
In respect of this effortless, hushed, performance, it should be noted that the acceleration is very impressive indeed. The Jaguar XJ-S will get from a standstill to 60 m.p.h. in 7 1/2 sec., to 70 m.p.h. in 9.6 sec., to 80 m.p.h. in a mere 12 sec. and go on to reach “the ton” in an elapsed time of only 18.1 sec. So great is the torque that almost all driving can be comfortably done in “D”, using kick-down only for really rapid overtaking. Similarly, it is perfectly acceptable to let the gearbox take care of its own upward and downward shifting, which it accomplishes extremely smoothly, giving maxima of around 55 m.p.h. and 94 m.p.h. coming out of the two lower speeds. The delightful smoothness of the big multi-cylinder engine is again seen in the brief time that the Jaguar takes to increase its pace from a steady speed onwards, in the order of three seconds from 40 to 60 m.p.h. for example, 3 1/2 sec. sufficing to go from 50 to 70 m.p.h., or at the lower end of the speed-scale, getting from a town crawl of 20 m.p.h. to a town speed-limit of 40 m.p.h. in fractionally over 2 1/2 sec. The top speed of such a car is of only academic interest to most road-going drivers these days, even abroad, but let us say that the XJ-S is good for at least 145 m.p.h.
It all makes for the most enjoyable motoring, especially as the driving-seat fits one snugly, is very comfortable, and appears to be of real leather — it has in fact leather facings. Veneer cappings and a tree-wood fascia are not used for this particular Jaguar model, which I think is absolutely correct for a fast car of this kind. Sighting along the bonnet gives one a feeling of purposeful motoring, but the side pillars somewhat obstruct the driving vision in that area. Providing that one accepts this Jaguar as a high-performance GT car, its rear-compartment space and the size of the box-like luggage boot (it takes 8.4 cu. ft. of luggage) are adequate. As the engine occupies all the under-bonnet room, the battery lives in the boot beside the upright spare wheel and is suitably ventilated. To gain access to the rear seat the squabs of the front seats fold forward, after neat latches on the squabs have been operated. The external door-handles are a little difficult to use until one has found out how to press the releases upwards, but the inside handles are well-placed. Three differently shaped keys are provided, one for ignition/steering-lock, one for the doors, and another for the boot and cubby-hole, although the boot can be opened without the key. There are two external rear-view mirrors, with internal adjustment. The windscreen is of the laminated type, there is tinted glass, the shallow sun-vizors are recessed into the roof, nylon pile-carpeting covers all the floor and the lower door-panels, and a Phillips stereo/radio cassette player is standard, with an electric aerial. The boot remains in darkness if the side lamps are off.
If the row of impressive switches that once made a Jaguar saloon so distinctive is not part of the XJ-S’s interior layout, nevertheless the fascia is effectively set out. The hooded speedometer and tachometer have between them four gauges with side-needles that move vertically. These show water-heat, oil-pressure, fuel-level and battery condition. They are not fully calibrated but are easy to see and oil-pressure normally reads 60 lb./sq. in. Lined along the top of the instrument nacelle are no fewer than 18 warning-lights, for turn-indicators, (two), rear-window demisting, fog-lamps (if fitted), headlamps full beam in use, battery-overcharge, a major fault, a secondary fault, ignition on, low fuel-level, hazard-warning on, coolant-level low, low brake fluid or a brake system malfunction, no oil-pressure, hand-brake on, seat-belts not fastened (that’s what it was!), side lamps defective and stop-lights defective — an electronic delight! The speedometer reads to 160 m.p.h., and the tachometer to 7,000 r.p.m., the latter with a warning area on its dial at 6,500 r.p.m. Both have white needles on black dials and the speedometer has very small k.p.h. markings, but no 30 m.p.h. mark. Silver edging picks out the dials, and the green fascia-illumination can be dimmed. The lamps are selected by a rotary switch convenient to the driver’s left-hand.
Two substantial stalk-levers are used, the left-hand one for the direction-indicators (which I prefer on a r.h. stalls), lamps’ dipping and flashing, the right-hand stalk looking after the two-speed windscreen-wipers, which also have a flick-action operated by pulling in the stalk. The wipers hesitate before coming up from their parked position, but wipe most effectively. The flat ends of both stalks carry operating instructions. The fascia carries four very large oblong press-switches, divided by an electric clock. These cover heating the rear window, hazard-warning, map-light and interior-lighting. The Jaguar possesses three interior lights and two map-lights.
The horn-push is the padded steering-wheel centre. The steering-column can be adjusted for reach after a big knurled ring surrounding it has been undone. There is lever-adjustment of the front-seat squabs. The hand-brake is unusual, as its lever lies horizontally on the right of the driving seat. It is completely out of the way, however, as it drops back after being applied, another upwards pull then releasing it — very neat! The gear-selector lever is pleasant to use and has the normal P,R,N,D,2,1 positions, although there is no indent as on a Rover 3500 quadrant to prevent an inadvertent move from D into N. At night each position is lit as it engages. The side windows are electrically raised and lowered by well-located switches on the rear of the centre console and also down on the console inasmuch for electric central-locking of the doors (surely dangerous, as the keys might be left inside the car?), and another device for lighting a cigar (the instruction book says). Smoker’s companions front and rear, a vanity mirror within the lockable cubby-hole and door-wells and rear-seat wells (but no fascia-shelf or other stowages) are other items of equipment. But there is a Ford-like lidded centre bin that is useful. The heavy doors have “keeps” that do not hold them open on a gradient.
One of the most acceptable features of the XJ-S is standard air-conditioning and heating, a system which by using two big rotatable knobs can be put to any of several temperature settings, which will then be automatically maintained. The temperature settings range from 65 deg., through 70 deg., 75 deg. and 80 deg. to 85 deg., and there are defrosting, high and low settings as well as the automatic setting. This air-conditioning is a great aid to comfortable, attention-free motoring. The Cibie biode quartz-halogen headlamps give a powerful beam and a sensible spread of light when dipped, which is done by flick-action of the I.h. control-stalk. The rear number plate is set high, away from road-dirt. The finish of the Jaguar XJ-S is generally of high quality and the styling a matter of individual opinion — I like it, except perhaps for the “vanes” flowing from the rear-window edges. The bonnet is hinged at the front and the petrol tank is behind the seats, its angled filler beneath a large flap on the near-side, the filler-cap having a lock with protective cover.
On the road the Jaguar XJ-S displays good manners in almost every way. The steering, with a big-thin-rimmed wheel, is geared three turns, lock-to-lock, and it is light, free from lost motion, and has mild but useful castor-return action. The suspension soaks up bad surfaces admirably and even when it can be felt working over really rough going it transmits nothing uncomfortable to the car’s occupants. The secure driving-seat and sense of the XJ-S’s compactness from within gives a driver full confidence from the outset and the Jaguar’s brakes contribute to this by their untemperamental and progressive power. The quietness of the engine is, of course, one of the car’s greatest attributes, and it matters not how fast the engine is turning. At a cruising speed of 70 m.p.h., if one can be so restrained, the r.p.m. equals 2,880. At 80 m.p.h. the engine runs at just under 3,300 r.p.m. and at 100 m.p.h. it is doing 4,100 r.p.m. There is also very little road-noise or wind-noise, the latter confined to some zizz round the off-side screen pillar, perhaps made by the mirror positioning. The steering is no longer, I thought, over-light and the cornering characteristic is initial mild understeer, with controllable oversteer on fast bends. The damping is admittedly set up for all-round comfort but can promote some float at times. The absolutely effortless continuing acceleration obviously contributes to the extreme safety of this 145 m.p.h. motor-car.
As to fuel consumption, I was hampered by slippery winter-weather conditions during the week in which I used the Jaguar, so the m.p.g. figure presented covers moderately fast driving on motorways and main roads, coupled with much slow driving and a great many cold-starts. It came out at 14.1 m.p.g. As the tank holds 20 gallons, the range, reckoning on between 13 and 16 mpg. in average useage, could well be a useful 290 miles, or over 300 miles if one is trying to save fuel. After standing outside in zero temperatures the V12 engine not only started very easily on the first application of the starter but was ready to pull away at once without stalling, and its low-speed torque is such that even under these adverse conditions full-lock on the power steering failed to trouble it, when other engines might have been overcome. The handbook, which comes in a leather wallet, recommends letting the engine warm-up at 1,500 r.p.m. on very cold days with the car stationary, but with no hand-throttle, how does one do this? Had I used this method, instead of driving circumspectly for the first few miles, fuel consumption would have been heavier. No oil was consumed, in 750 miles, which was just as well, because the oil filter cap was difficult to move, inspite of its crossbar. The bonnet is self propping but its release lever is on the wrong side of the driving compartment and has to be operated again to secure the bonnet in the shut position. The Jaguar’s rear compartment is cramped for two normal sized adults but the divided seat was reported as very comfortable by the two ladies that occupied it for half-a-day’s motoring. Reverting to the ventilation the hot air vents at the fascia extremities can be cut off, but not the up and down adjustable centre vents. Incidentally, all dials and controls are cleanly marked.
The Jaguar XJ-S is a very fine car indeed and when you remember that it costs only £19,187 whereas, for instance, an Aston Martin V8 sets you back a matter of £34,498, a BMW 635CSI £18,950, a Ferrari 308GTB £20,100, a Maserati Merak £22,998 and a Porsche 928 £21,872, and remembering the Jaguar’s quiet-running, its impeccable twelve-cylinder engine, and its overall excellent road manners, there would seem to be no good reason at all for any Britisher who is in the market place for a high-performance car to rush off and buy a foreigner; unless he is seeking a raspy, rorty sort of GT machine – the Jaguar’s V12 power unit is muted indeed, in comparison. The Jaguar XJ-S is certainly a motor-car that I would gladly own. It is manufactured by the Jaguar-Rover-Triumph Section of BL, at Browns Lane, Allesley, Coventry, CV5 9DR and after driving one I find it astonishing that there are not more on the road. – W.B.