Featured here is a great looking 1954 Jaguar XK-120. The Jaguar XK- 120 was introduced in 1948. The 120 in it’s name meant that the automobile has a top speed of 120 MPH. At the time, the XK-120 was the fastest production car in the world. Zero to 60mph took 10 seconds. The car set many and now legendary speed records and Jaguar used its engine for decades.

1954 jaguar 120
1954 Jaguar XK-120

The Jaguar XK-120 was designed as an entry-level sports car to be offered to the masses. It was Jaguar’s first dip back into the sports-car pool since it had produced the SS100.

Demand for the XK 120 exploded, particularly in the United States, where drivers had never seen a postwar sports car. It were these type cars that a few years later would spark the introduction of the Chevy Corvette and Ford Thunderbird.

The demand for the XK-120 was strong. Once Jaguar had caught up  with this demand, the production of steel bodied models went smoothly. Jaguar then developed the coupé to expand appeal. Aside from the obvious addition of a roof, the biggest difference between the coupe and roadster was the use of a mostly steel floor pan in place of plywood.

Jaguar at first planned to build only 200 units of the new sports car. The public’s very enthusiastic reception at the 1948 Earl’s Court Show made it necessary for Jaguar to put it into full production.

jaguar sports carsJaguar’s Straight Six

The engine’s development was headed by William Heynes, who was aided significantly by Walter Hassan and Claude Bailly.

They came up with a straight six cylinder engine displacing just over 3.4 liters.

Unlike the push-rod and side-valve engines previously used, the new ‘XK‘ featured twin overhead camshafts. In normal street tune the engine could produce 160 HP. Tuned for competition  with the compression increased to 9.0:1, the six cylinder produced 180 HP. Both versions used a twin SU Carburetor setup. Power was transferred to the rear wheels through a four speed gearbox bolted directly to the engine. As a side note, originally two engine versions were planned, a four and six cylinder, but the four cylinder model was dropped and all the focus was on the new six cylinder.


The new Jaguar XK-120 design was unique. The two seat roadster with its classically simple flowing lines, slender tail end and exotic flush sided body was a giant leap forward in sports car design at the time. The XK-120 was gorgeous, featuring a swooping and streamlined design that made it quite clear the model meant speed and performance.

1954 Jaguar XK-120 Specifications

The XK 120’s 3.4 liter straight-six engine utilized chain-driven dual overhead camshafts and a hefty crankshaft that carried seven oversize main bearings. Featuring aluminum heads and pistons, the engine produced 160 horsepower with twin carburetors.

Four speed manual gearbox.

Lockheed four wheel drum brakes.

Suspension was by wishbones and torsion bars at the front and a live axle with transverse leaf springs.

Dimensions included a length of 173.0 inches, width of 62.0 inches, height 52.5 inches and a wheelbase of 102.0 inches. Curb weight 2921 lbs.

Originally, only 200 examples were intended to be produced, but after the car’s tremendous reception at Earls Court, it was obvious that the automaker could sell many more than that. In total, 12,055 XK-120 roadsters, coupes, and drophead coupes were produced from 1948 to 1954, including 7,374 steel-bodied roadsters. Of the 12,055 units produced, 7,631 were Roadsters, 2,678 were Fixed Head Coupes and 1,769 were Drop Head Coupes.

See the additional Auto Museum Online photo articles on the links below…..

1957 Jaguar XK-140

1958 Jaguar XK-150

Jaguar XK-120 Collector Cars and Values

jaguar xk-120 dashboard
XK-120 dash

The Jaguar XK-120 represented a sports car production breakthrough.

This model is a beautiful representation of one of Jaguar’s most successful attempts at sports car and race car production, and it is a piece of auto racing and Jaguar competition history.

The difference between somewhat more famous cars and the Jaguar XK-120s is that while rare Ferraris and Maseratis command a great deal more money at auction, the more prevalent XKs cost less and remain reliable as casual drivers.

jaguar xk 120Current price data shows that the XK-120 Roadsters and Drop-Head Coupes are listed anywhere from about $90,000 to $190,000. The Fixed Coupes are generally listed well under $100,000.Generally the earlier year models command the higher price.

Three references for this article and excellent books you may enjoy include…..Jaguar Sports Cars (A Foulis motoring book) by author Paul Skilleter…..Jaguar XK120,XK140,XK150 Sports Cars by Karl Ludvigsen and Original Jaguar XK: The Restorer’s Guide by author Philip Porter.

(Photos and article copyright Auto Museum Online)