Although the XK120 was the fastest, most exotic car that Britain offered in 1948, it came about almost by accident.
In 1945, Jaguar Cars offered a range of stylish sedans and tourers, but used bought-in engines. Company founder William Lyons planned a new sedan with a brand new Jaguar-made engine, designed in secret during World War II.
This twin-camshaft straight-six was a masterpiece. Flexible and powerful, its basis was a cast-iron block with a seven-bearing crankshaft. On top was an all-alloy crossflow Weslake cylinder head. It had two noise reducing timing chains, and twin 1.75in (4.5cm) SU carburetors. It looked superb with its polished aluminum cam covers, and stove-enameled exhaust manifold.
Delays in the sedan’s development meant that Jaguar had no car in which to install its showpiece. So William Lyons hastily constructed a sports car body on a shortened sedan chassis, thinking it might generate publicity and act as a rolling testbed.
The result of this was breathtaking: the XK120 was beautifully, classically proportioned and confirmed Lyons’ genius as a stylist. It was fast, too. On a motorway at Jabbeke in Belgium, test driver Ron Sutton achieved 126.5mph (203.5kph), and over 132mph (212kph) with the windshield and hood removed.
Jaguar was deluged with orders, but a new problem arose: satisfying demand. Indeed, most production was exported to the US; one rarely saw an XK120 on British roads.
“It felt comfortable in the wet and, with the Jag, it was an advantage because it lightened the steering and saved the brakes. I took the lead on the second lap and won.”
British racing driver, stirling moss, who won the 1950 tourist trophy race in an xk120, aged 21
Video model car Jaguar XK120
Specification model car Jaguar XK120
YEAR REVEALED: 1948
PLACE OF ORIGIN: Coventry, Warwickshire, UK
HISTORICAL STATUS: production car
ENGINE: six-cylinder, 209ci (3,442cc)
MAXIMUM POWER: 160bhp
LAYOUT: front-mounted engine driving the rear wheels
BODYWORK: two-door two-seater roadster and coupé
TOP SPEED: 124mph (200kph)
NUMBER BUILT: 12,055