The XK150, the final and most magnificent model of Jaguar’s ‘XK’ series, was introduced in 1957. It evolved from the XK120 and XK140, retaining the same chassis, 3.4-litre engine, and four-speed Moss transmission.
The new, wider body offered more interior space and better visibility with a single-piece wrap-around windscreen. A major improvement was the addition of Dunlop disc brakes, solving the fading issue of earlier drum brakes and providing stopping power to match the car’s speed.
The engine output remained at 190bhp, similar to the XK140, with performance unchanged. However, ‘Special Equipment’ and ‘S’ versions provided 210bhp and 250bhp, respectively, with the ‘S’ featuring a Weslake-developed cylinder head, high-compression pistons, triple SU carburettors, and twin electric fuel pumps.
The XK150 ‘S’ offered a Thornton Powr-Lok limited-slip differential. While steel wheels were standard, most XK150s featured SE specification with center-lock wire wheels. The chrome Jaguar mascot was an optional extra for the first time.
In late 1959, the XK150 introduced a 3.8-litre engine from the Mark IX saloon, available in standard (220bhp) or ‘S’ (265bhp) tune. This engine offset the car’s increased weight, enabling it to exceed 130mph (209km/h) in tests.
