Jaguar XK150S Roadster

First introduced in the fall of 1957, the XK150 was intended to directly compete with the BMW 507 and Mercedes 300SL. As the third and final evolution of its series, the XK150 was the best and most highly developed variant. Although similar in overall design to its predecessors, styling revisions included the replacement of the traditional cut-down doors with a higher, more subtle beltline. The front was changed with a widened grille and a curved, one-piece windscreen.

Performance continually increased, from the basic XK120 and the SE version through the XK140 MC with the “C-Type” cylinder head and on to the XK150 with its straight-port “S” head. Race-bred four-wheel disc brakes were added to the XK150 and provided stopping power to match the car’s performance levels. In fact, the XK150 was the very first series-production car ever to feature power-assisted disc brakes at all four corners.

In the spring of 1958, the high-performance XK150 S model was introduced, featuring a gold-colored, Harry Weslake-modified straight-port cylinder head that helped boost the output of the 3.4-liter engine from 190 to 250 hp. The ‘S’ also enjoyed improved fuel flow by way of three large SU carburetors, a usefully higher compression ratio (9.0:1 versus 8.0:1) and more-aggressive camshaft timing. Every ‘S’ model came standard with a four-speed manual gearbox with overdrive. The 3.4-liter “six” was enlarged to 3.8 liters of displacement for 1960, and output rose to 265 bhp, allowing the 3.8-powered XK150 S to achieve top speeds in excess of 135 mph.

This car was auctioned off by RM Auctions in January of 2011 at the Arizona Biltmore Resort & Spa, Phoenix, Arizona and in June of 2011 at the Syon House, London.

265 bhp, 3,781 cc DOHC inline six-cylinder engine with three SU carburetors, four-speed manual gearbox with Laycock de Normanville overdrive, independent front suspension with wishbones, coil springs, torsion bars and anti-roll bar, rigid rear axle with semi-elliptic leaf springs, and four-wheel hydraulic disc brakes. Wheelbase: 102"

Source: RM Auctions
Photo Credit: Copyright Tim Scott

Gallery: Jaguar XK150S Roadster