Jaguar XK’s

1948 - 1961



Jaguar XK120

The Jaguar XK120 was a sports car manufactured by Jaguar between 1948 and 1954. It was the first post-war sports car from the marque, succeeding the SS 100 which ended production in 1940 after the start of World War II in Britain. The XK120 was launched at the 1948 London Motor Show as a test bed and show vehicle to highlight the new Jaguar XK engine. The car caused a sensation, which persuaded William Lyons to put it into production as a standard model.

The first cars manufactured in 1948 and 1949 had hand built aluminium bodies on an ash frame. Jaguar built 240 of these alloy bodied cars prior to moving to a more mass production XK120 in order to meet the demand for this popular model. With the 1950 model year a production version had a steel pressed body with alloy doors, bonnet, and trunk skin. Other features included torsion bar front suspension, and a removable windscreen.

Power came from a dual overhead cam 3.4L straight-6 engine, Jaguar's famous XK engine. With an alloy cylinder head and twin side draft SU carburators, the XK engine was very advanced for a mass produced unit, developing 160 bhp with the standard 8:1 compression ratio. A 7:1 low compression version of the engine was also available to cope with low quality fuel. This same basic design of the XK engine was used in 3.8L and 4.2L versions into the late 1980s.

The Roadster had a very light weight canvas top and removable side curtains screwed to the doors, which had no external handle - to open them you reached through the screen to pull a cord on the inside. It also had a removeable windscreen, which could be removed so that "aeroscreens" could be fitted. The DHC or Drop Head Coupe had a padded top and roll up windows. Both the FHC and DHC had an elegant wood veneer dash, whereas the roadster's was leather. All models were manufactured with spats to cover the back wheel arch which enhanced the streamlined look, but when optional (from 1951) wire wheels were fitted, the spats had to be removed to make room for the hub spinners. There was also an M version (called SE for Special Equipment in England) which included increased power, stiffer suspension, dual exhaust, and wire wheels.


The roadster was tested in 1949 and had a top speed of 124.6mph (200.5km/h) and could accelerate from 0-60mph (97km/h) in 10.0 seconds. A fuel consumption of 19.8miles per imperial gallon (14.3L/100km/16.5mpgUS) was recorded. The test car cost £1263 including taxes.


The Jaguar XK140 was a sports car manufactured by Jaguar between 1954 and 1957. Upgrades over its predecessor, the XK120, included better brakes, rack and pinion steering, and modern tube type shock absorbers instead of the older lever arm design. The name referred to its 140mph (225km/h) top speed. The XK140 continued to feature the famous Jaguar XK engine with the SE mods from the XK120 as standard, now delivering 190bhp (142kW) at 5750 rpm. The special C-Type cylinder head was also carried through from the XK120 catalogue as an option, providing 210bhp (157kW).

With the introduction of the XK140 in late 1954 (all sold as 1955 models), the primary visual change was the more substantial front and rear bumpers, with large overriders. Another new feature was the provision of modern flashing direction indicators, operated by a separate switch on the dash. The twin amber lights positioned above the front bumper helped to distinguish the XK140 - until XK120 owners started installing the same equipment. The front grill was the same size as the grill on the XK120, but was now a one piece cast unit with fewer, thicker vertical slats. Above the grill was the Jaguar mascot, and a chrome strip which extended back over the bonnet. This strip continued down the centre of the boot (trunk) lid, where it contained a red shield with the words 'Winner Le Mans 1951-3' inscribed in gold.


The interior was also more comfortable for taller occupants with the addition of 3inches (76mm) in length. This was achieved by moving the engine forward which allowed the firewall and dash location to be relocated as well. The new arrangement left no room for the XK120 battery compartment, and the single battery was now repositioned low down inside the wing on the inlet side, making it almost impossible to replace.

In 1956, the XK140 was the first Jaguar sports car to be offered with an automatic transmission. As with the XK120, the availability of wire wheels and dual exhausts were options although most cars imported into the United States had wire wheels. Cars with disc wheels continued to be offered with spats closing the rear wheel arch. The XK140 was available in three body styles. A Roadster or OTS (Open Two Seater) which had a light canvas top assembly that when lowered fitted behind the seats and thus completely disappeared inside the body. The interior of the Roadster was very sparse with no wood embellishments, but with a leather dash. Just like the XK120 Roadster, the XK140 OTS or Roadster had removable canvas and plastic side curtains on light alloy doors. The DHC or Drop Head Coupe had a more substantial padded top that when lowered sat above and outside the body of the car, it also had a fixed windscreen (unlike the removeable windscren of the OTS). The DHC also had roll up windows and a very elegant veneered dash, both of which featured on the FHC or Fixed Head Coupe as well. As a gesture to practicality, a jump seat was added to both coupe mode.

The Jaguar XK150 was a sports car produced by Jaguar between 1957 and 1961. It replaced the previous XK140. Initially it was available in Fixed Head Coupe (FHC) and Drop Head Coupe (DHC) versions. The Open Two Seater (OTS) Roadster model was not launched until 1958. Token rear seats were fitted in the coupes. 

For the first time a one piece windscreen was used and the wing line no longer dropped as much over the doors. The bonnet was widened and opened down to the wings and on the OTS the bulkhead was moved back to make it about 4inches (102mm) longer. The car was available at various times in Red, Pearl Grey, White, Indigo Blue, Claret, Cots wold Blue, Black, Mist Grey, Sherwood Green, Carmen Red, British racing Green, Cornish grey and Imperial Maroon.


Inside the car the walnut dashboard went, to be replaced by one trimmed in leather. On the early Drop Head Coupes, an aluminum center dash panel with an X pattern engraving was fitted which looked similar to the early 3.8 E-type. It was discontinued after June 1958. The doors were thinner giving more interior space.

The standard engine, the same as fitted to the XK140, was the 3.4 litre DOHC Jaguar straight-6 rated at 180 SAE bhp at 5750 rpm but most cars were fitted with the SE engine that had a modified cylinder head with larger exhaust valves rated at 210 SAE bhp at 5500 rpm. Twin 1.75 inch SU HD6 carburettors were fitted. In 1958 the S model was launched with three 2 inch SU HD8 carburettors and a straight ports cylinder head giving a claimed 250 SAE bhp. The engine capacity was increased in 1958 to 3.8 liters by increasing the bore. Claimed output was now 220 bhp for the standard and 265 SAE bhp for the S version.



Inevitably, the first XK150 were slower than their predecessors, but the deficit was corrected in the spring of 1958 with a 3.4-liter "S" engine rated at 250 hp. For 1960, Jaguar bored its 3.4 to 3.8 liters, rating this option at 220 hp in standard tune or 265 in "S" form. A 3.8- liter 150S could top 135 mph and sprint from 0-60 mph in around 7.0 seconds, thus restoring whatever verve the XK had been missing.



Four-wheel disc brakes appeared for the first time although it was theoretically possible to order a car with drums. Either wire wheels or disc wheels could be specified. Suspension and chassis were very similar to that on the XK140. Steering was by rack and pinion; power steering was not offered. Production totaled 2265 Roadsters, 4445 Fixed Head Coupes and 2672 Drop Head Coupes.