Background
It’s hard to imagine but when Jaguar launched the XK120 in 1948 it did so with modest expectations. Intended simply as a show car to debut the new 3.4-litre twin-cam XK engine, the svelte roadster stunned audiences and caused such a stir that Jaguar had no choice but to put it into production.
Originally planned to be limited to just a few hundred cars, demand was so overwhelming that Jaguar transitioned from an aluminium body over ash frame to all-steel construction by 1950 and went on to build over 12,000 units.
With a top speed of 120mph – hence the name – the XK120 was the fastest production car in the world at the time. It wasn’t just speed that set it apart: the car’s sleek curves, superb engine and accessible price point made it an icon almost overnight.
The XK engine, developed under the direction of Jaguar founder Sir William Lyons and engineer William Heynes, would go on to serve Jaguar for decades. But in the XK120 it was first seen in roadgoing form: a 3.4-litre straight six with hemispherical combustion chambers, twin SU carburettors and a claimed 160bhp in standard tune.
The car handled well for its day, rode beautifully and proved competitive in motorsport, including the Mille Miglia, Le Mans and countless privateer events.
But despite its strengths, the XK120 wasn’t perfect. The cockpit was cramped, the steering was heavy, and the drum brakes struggled under spirited use. As Jaguar evolved into a larger and more ambitious company, and as customer expectations rose, an update became inevitable.
The result arrived in 1954 in the form of the XK140. At first glance, the new car looked much like its predecessor, but under the skin – and to the trained eye – it had been significantly reworked. One of the key aims was to make the car more usable, especially for the crucial American market where the XK line had found a loyal following.
To that end the body shell was subtly but meaningfully altered. The engine and bulkhead were moved forward by three inches, creating more legroom and allowing for more comfortable seating. The interior was redesigned to offer better ergonomics, and the addition of rack-and-pinion steering improved both precision and driver feedback.
Cosmetically the XK140 gained heavier bumpers and a more prominent grille with vertical slats replacing the finer horizontal design of the 120. Badging was updated and a pair of chrome strips ran the length of the bonnet and boot lid. Inside the dashboard now featured walnut veneer rather than painted metal, adding a touch of extra luxury.
Under the bonnet, the car retained the 3.4-litre XK engine, but power was increased to 190bhp in standard trim. Buyers could also specify the Special Equipment (SE) model, which featured the cylinder head from the C-Type racer, upping power to 210bhp. This meant genuine 120mph performance again but with more refinement, better handling and improved braking thanks to the now-standard telescopic dampers.
The XK140 was offered in three body styles just like its predecessor: the Open Two-Seater (OTS), the Fixed Head Coupé (FHC), and the Drophead Coupé (DHC). The OTS remained the sportiest and lightest, while the DHC added more weather protection and creature comforts. The FHC, with its sweeping roofline and full glass side windows, offered the best insulation and arguably the most elegance.
Production of the XK140 ran until 1957 at which point it was succeeded by the XK150 – an even more modernised and heavier car that steered the series more in the direction of a grand tourer than a sports car.
Whether as a nimble roadster for weekend blasts or a coupé suited to longer touring events, the XK140 remains a truly desirable classic. It stands as a testament to Jaguar’s rapid post-war growth and its ability to blend performance with elegance.
More than a mere stepping stone between two other icons, the XK140 has rightly earned its place as a classic in its own right.
