The XK150 replaced the XK140 in May 1957, launching as a fixed head and drophead coupe with the roadster following nearly a year later — the reverse of the XK120's order.
Specification
| Item | Detail |
|---|---|
| Engine, 3.4 | 3,442 cc, 83 × 106 mm |
| Engine, 3.8, from October 1959 | 3,781 cc, 87 × 106 mm |
| Power, 3.4 SE | 210 bhp at 5,500 rpm |
| Power, 3.4 S | 250 bhp at 5,500 rpm |
| Power, 3.8 | 220 bhp at 5,500 rpm |
| Power, 3.8 S | 265 bhp at 5,500 rpm, gross |
| Gearbox | Moss four-speed; overdrive and automatic optional |
| Brakes | Four-wheel servo-assisted 12 inch Dunlop discs, from launch |
| Steering | Rack and pinion. Power steering never offered |
| Built | 9,385 or 9,382 |
Two things commonly got wrong
A catalogued 190 bhp base car existed on paper but was effectively not built — production XK150s were all to Special Equipment specification at 210 bhp. Publishing 190 as the standard figure describes a car almost nobody bought.
And you will find it stated, including by a marque club, that 3.4 cars had drums and only the 3.8 had discs. That is wrong. Every production XK150 had four-wheel discs from launch in May 1957.
What changed from the XK140
Four-wheel Dunlop disc brakes. A one-piece curved windscreen in place of the split screen, a wider body and a raised wing line. Wind-up windows on the roadster in place of sidescreens.