The XK120, introduced in 1948 at the London Motor Show, was a landmark sports car for Jaguar. It marked the debut of the XK engine and set the stage for the XK series. The XK120 was powered by the XK engine, a 3.4-liter inline-six that became renowned for its performance. At the time of its introduction, the XK120 had a top speed of 120 mph, making it the fastest production car of its era.

The XK140 succeeded the XK120 and brought improvements such as more interior space, improved suspension, and rack-and-pinion steering. It retained the XK engine but with some refinements. The XK140 was available in roadster, fixed-head coupe, and drophead coupe versions.

The XK150 was the final iteration of the XK series before the E-Type’s introduction. It featured a more refined design, including a one-piece windshield and a larger grille. The XK150 aimed at combining comfort with high performance. It was available in various body styles, including roadster, fixed-head coupe, and drophead coupe.