The 3.4-litre Jaguar Engine is one of the marvels of the age. In racing tune, it achieves tremendous speeds, and in normal form it powers a range of cars from six-seater luxury models to the sports XK types. Now, a “hotter” version of this basic engine has been made available, and it is used in the ultra-high speed XK 150S two-seaters.’ – John Bolster, Autosport.

What would turn out to be the final glorious incarnation of Jaguar’s fabulous ‘XK’ series of sports cars arrived in 1957. As its nomenclature suggests, the XK150 was a progressive development of the XK120 and XK140, retaining the same basic chassis, 3.4-litre engine and four-speed Moss transmission of its predecessors while benefiting from a new, wider body that provided increased interior space and improved visibility courtesy of a single-piece wrap-around windscreen, replacing the XK140’s divided screen. Cleverly, the new body used many XK120/140 pressings, the increased width being achieved by means of a 4″-wide central fillet. A higher front wing line and broader radiator grille were other obvious differences, but the new model’s main talking point was its Dunlop disc brakes. Fade following repeated stops from high speed had been a problem of the earlier, drum-braked cars, but now the XK had stopping power to match its prodigious straight-line speed.

Introduced in the spring of 1957, the XK150 was available at first only in fixed and drophead coupé forms, the open roadster version not appearing until the following year. At 190bhp, the engine’s maximum power output was identical to that of the XK140, so performance was little changed. ‘Special Equipment’ and ‘S’ versions came with 210 and 250bhp respectively, the latter delivering an astonishing 0-97km/h time of 7.3 seconds and a top speed of 219km/h. This was achieved by the introduction of the Weslake-developed ‘straight-port’ cylinder head, high-compression pistons, triple 2″ SU carburettors and twin electric fuel pumps. Overdrive and a Borg-Warner automatic gearbox were the transmission options, the latter becoming an increasingly popular choice, while a Thornton Powr-Lok limited-slip differential was available for the XK150S. Steel wheels remained the standard fitting, though XK150s so equipped are a great rarity, as most were sold in SE (Special Equipment) specification with centre-lock wire wheels. The much-admired chromed Jaguar mascot was made available as an optional extra on an XK for the first time.

Bolster concluded his review thus: ‘It combines extreme performance with perfect manners to a quite exceptional degree, and it has a sporting appearance that is entirely suitable for the most formal occasions. Being a Jaguar, it is really hardly necessary to remark that it represents outstanding value for money.’

Manufactured in June 1958, left-hand drive chassis number S830725DN was despatched to Jaguar Cars, New York, USA, in July 1958. Its original body colour was Mist Grey, its interior trim and soft top were dark blue, a colour scheme which it sports today. It was equipped with its Moss four-speed gearbox, as well as the De Norman overdrive transmission. The car was reportedly kept for showroom display by Jaguar Cars, NY, and was first registered by a private owner in 1961. Early in 2000, it returned to Europe, residing in Belgium ever since.

The vehicle’s current owner had the engine’s top-end rebuilt, sump gaskets/seals renewed, the clutch replaced and the brake system overhauled (new master cylinder and lines), all work for which bills are available. Prior to this, between 2003 and 2008, the car underwent painstaking ‘last nut and bolt’ work by Classic Car Service BVBA in Antwerp to restore it to concours condition.

Since the completion of the restoration work, the car has never been entered into competition; it has been driven sparingly by its owner, with the love and care owed a splendid and characterful ‘old lady’.
This most desirable member of the XK150 family is offered with JDHT certificate – confirming all matching numbers – 2007 FIVA Passport, Belgian registration papers, an extensive portfolio of restoration photographs, sundry invoices and rare original toolkit.