The Jaguar XJS, introduced in 1975, remains one of the most controversial models ever to emerge from Browns Lane: a heavyweight GT far removed from its predecessor, the immortal E-type. Nonetheless, it survived for almost 21 years, enduring some of the most tumultuous periods of Jaguar’s history. This week, we look at the development and lengthy evolution of the XJ-S, from 1975 to 1996.

JAGUAR LOOKS BEYOND THE E-TYPE

We can think of few challenges less enviable than designing a replacement for the legendary Jaguar E-type. A descendant of Jaguar’s spectacular D-type racers of the late 1950s, the E-type had bowed in March 1961 to international acclaim. It was fast, nimble, keenly priced, and gorgeous, and while its later iterations showed signs of middle-age spread, they remained among the most beautiful cars in the world.

Jaguar first started thinking seriously about a successor to the E-type in the fall of 1966. The new car, known internally as XJ21, was to retain the basic chassis layout and dimensions of the long-wheelbase E-type 2+2, but with new styling, a wider track, better heating and ventilation, and provision for convenience options like electric windows.

Like the E-type, the XJ21 would have been offered in three body styles: two-seat and 2+2 fixed-head coupes (sharing the same wheelbase, but with different rooflines) and a two-seat convertible. Instead of the venerable XK six, the XJ21 would have offered either a new 60-degree 3.6-liter (217 cu. in.) V-8 or Jaguar’s upcoming 5.3-liter (326 cu. in.) V-12. If that weren’t enough, at one point Jaguar also envisioned a smaller, cheaper companion model, the XJ17, riding the shorter wheelbase of the early two-seat E-type and offering a choice of V8s: either the new 3.6-liter engine or the 2.5-liter (156 cu. in.) OHV engine from the Daimler V-8 250 sedan.

That was an ambitious lineup for an automaker of Jaguar’s size. While the firm offered a surprisingly broad range of products in the mid-sixties, including the compact Mark 2 sedan (later renamed 240/340), the midsize S-type (later 420), the big Mark X (later 420G), and even a handful of Daimler limousines, Jaguar’s total volume was still well short of 30,000 units a year. As for the E-type, for all its success, it was still a low-volume product in absolute terms. Total Series I production amounted to fewer than 35,000 units between 1961 and 1968. With those kinds of numbers, the XJ21 and XJ17 promised to be an expensive proposition.

Jaguar had been doing well, acquiring Daimler, Coventry Climax, and Guy Motors earlier in the decade, but by 1965, chairman and managing director Sir William Lyons recognized that the company could not afford to remain independent much longer. In mid-1966, he negotiated a merger between Jaguar and the British Motor Company (BMC).

Although Jaguar retained its autonomy following the merger, hopes of greater financial stability (and additional development capital) were in vain. BMC’s losses, already worrisome, continued to mount, and by 1967, the British government was convinced that the only way to avoid a complete collapse was a merger between BMC and rival Leyland Motors. The result was the formation in the spring of 1968 of the massive British Leyland Motor Company (BLMC), under the leadership of Leyland’s Donald Stokes.

Sir William managed to secure a favorable position as board member and deputy chairman of BLMC, but Jaguar’s position was becoming increasingly difficult. The launch of the XJ4 sedan, which would replace most of the company’s existing sedan lines, had been delayed until the fall of 1968, and its intended V-12 engine was still far from ready. With development funds in short supply, the XJ17 never got off the ground, and the XJ21, whose design was close to production form by the time of the BLMC merger, no longer seemed economically viable; it was canceled in 1969. The Series III E-type, the first production Jaguar with the new V-12, went forward, but it arrived more than 18 months behind schedule, debuting in March 1971.

THE SPORTING XJ: THE XJ27/XJ28

While the Series III would survive for nearly three years, it was clear that the E-type could not go on indefinitely. The new engine restored the performance that U.S. emissions standards had eroded, but the E-type’s body had other deficiencies that were not easily rectified, like awkward entry and exit and sub-par ventilation. Worse, it had been designed well before the passage of the first U.S. motor vehicle safety standards, and getting the aging body to pass the more stringent rules slated for the mid-seventies would be difficult, if not impossible.

Although the company could not afford a completely new sports car platform, there was another possibility. Since Jaguar was busily replacing its sedan lineup with the new XJ4 series (the XJ6 2.8, 4.2, and equivalent Daimlers), a coupe built on the XJ4 platform was a logical next step. Design director Malcolm Sayer had proposed such a car, initially known as the XJ4 GT, shortly before the launch of the XJ6 in September 1968. If Jaguar had had the resources, it would probably have developed both the XJ21 and the XJ4 GT, but as the XJ21 project collapsed, the XJ4 GT emerged as its replacement.

Initially, Jaguar planned to offer the GT as both a 2+2 coupe, known internally as XJ27, and as a convertible, known as XJ28. The latter was canceled around 1970, both for cost reasons and because it appeared U.S. safety regulations would soon outlaw open cars. Unlike the E-type, whose body structure was a blend of monocoque and space frame, the XJ27 was a steel monocoque based on a shortened version of the XJ4 sedan floorpan. It shared the XJ4’s double-wishbone front suspension, differing primarily in spring, damping, and roll rates. Its rear suspension and subframe were also borrowed from the XJ4, with inboard disc brakes and dual coil springs and dampers on each side; the XJ27 added a rear anti-roll bar not found on the sedan. Like the XJ4, the XJ27 would have Adwest rack-and-pinion power steering, albeit with a faster ratio and a more rigidly mounted rack for greater precision.

The styling of the XJ27 was originated by Malcolm Sayer with substantial input from Sir William himself. Although Sayer had also been responsible for the E-type and its predecessors, the XKSS and D-type, the XJ27 was a considerable departure from Jaguar’s previous sports cars. Sayer was an aerodynamicist by training — his early career included a stint at the Bristol Aeroplane Company, where he helped develop the Bristol Blenheim and Beaufighter — and his goals for the XJ27 including substantial reductions in both drag and lift. Jaguar later claimed that the production car’s CdA (the product of drag coefficient and frontal area) was 10% lower than that of the Series III E-type, while front-end lift was halved.

Sayer’s aerodynamic aspirations were responsible for the XJ27’s most controversial styling feature: its flying-buttress sail panels and recessed backlight. This was not a new idea, first appearing on mid-engine race cars in the early sixties and followed in production by Ferrari’s Dino 206, GM’s 1966-67 A-body intermediates, and the 1968 Dodge Charger; it would become ubiquitous on mid-engine sports cars of the seventies. Some of the sketches for the earlier two-seat, fixed-head XJ21 had featured similar-looking extended sail panels, which appear to have been part of the XJ27’s brief from the beginning. Even some Jaguar stylists were dubious about the look, but the flying buttresses remained part of the design even after Malcolm Sayer’s untimely death in the summer of 1970.

At launch, the XJ27 would be offered with only one engine: the 5,343 cc (326 cu. in.) SOHC V-12 from the Series III E-type and XJ12 sedan. The planned 3,563 cc (217 cu. in.) V-8 — essentially a V-12 shorn of four cylinders — was proving troublesome, in large part because it shared the V-12’s 60-degree bank angle. The V-8’s output was respectable, but even with balance shafts, its refinement was lacking. It was finally canceled in the fall of 1971. A mooted 2,672 cc (163 cu. in.) slant six, intended for future sedans, eventually met a similar fate. As far as we’ve been able to determine, there were no serious plans to offer the XK six in the XJ27, although a six-cylinder model would emerge some years later.