Following on from the outstanding success of the C-type, the D-type was to break fresh ground as it was a monocoque construction. To its ‘tub’ of magnesium alloy was attached a tubular front sub-frame which carried the engine, steering and front suspension. With its bag tanks for the fuel, the D-type borrowed a good deal from aircraft practice. It was created by Bill Heynes and Malcolm Sayer.

The D-type was first taken to Le Mans in 1954 with high hopes pinned on it. The cars had engine problems early on in the race. With the cause diagnosed, the drivers began a valiant battle to make up lost ground. Further frustration was experienced when Tony Rolt was pushed off by a slower competitor and the heavens opened to almost flood the track – Duncan Hamilton was getting wheelspin at 170 mph!
After many hours of driving as fast as they dared, during which the D-type ran faultlessly, they finished just one minute and 45 seconds behind the winning Ferrari after 24 hours. 

Revenge was gained a few weeks later when Peter Whitehead and Ken Wharton won the 12 hour race at Reims.

Jaguar had now carved for itself a fine reputation. It had in production a superb large saloon and a very fine sports car, but it needed a high-volume smaller car.  

One million pounds in 1955 was a very significant amount and that was the investment expended on designing and developing Jaguar’s important new compact saloon. The saloon’s unitary method of construction was a new venture for Jaguar. This type of body, in which the basic shell doubled as the chassis, had the advantage of saving weight and being inherently more rigid.

The decision was made to use a reduced version of the 3.4 litre six cylinder. Thus a 2.4 litre was produced and fitted to the new saloon, the model simply being known as the Jaguar 2.4. Indeed, this was to be an incredibly important model for Jaguar and would remain in production, in one form or another, for more than 10 years.

Le Mans 1955 had all the makings of a titanic struggle. British driver, Mike Hawthorn, joined the Jaguar team as Moss had moved to Mercedes-Benz in his quest for Grand Prix success. For the first hour or so a magnificent race was fought by Castellotti in the Ferrari, Fangio in the Mercedes, and Hawthorn in a D-type. The D-types had been revised and now wore ‘long-nose’ bodywork to improve air penetration. A new ‘wide angle’ cylinder head with increased valve sizes had been designed with a resultant increase in power to 275bhp. Sadly this was the year of the tragic crash with a large number of spectators killed when one of the Mercedes crashed into the crowd. Fangio and Hawthorn were locked in a thrilling tussle, passing and re-passing until the remaining Mercedes were withdrawn. Hawthorn and Ivor Bueb in the D-type went on to victory.

Le Mans 1956 was a curious one for Jaguar. On the second lap, two of the cars collided with each other in the Esses and the third was put out of contention by a split fuel line. It would have been a complete disaster had it not been for the fact that Jaguar had, in effect, a back-up team. A private Scottish team by the name of Ecurie Ecosse had been racing Jaguars for several years and were running two D-types. Luckily for Jaguar the one driven by Ron Flockhart and Ninian Sanderson crossed the line in first position.

At the end of 1956 Jaguar announced that it intended retiring from motor racing. There was no factory D-types at Le Mans in 1957, but there were five private entries. All five D-types finished, the Ecurie Ecosse cars driven by Flockhart and Bueb and Sanderson and Lawrence, taking the first two places, the French duo of Lucas and Mary third, and the Belgian pairing of Frere and Rousselle fourth. Duncan Hamilton and American Masten Gregory came home sixth.

In 1957, the Jaguar XKSS, a road-going version of the Jaguar D-type racing car was released. However, XKSS production was abruptly halted after just 16 had been made due to an enormous, and potentially catastrophic fire at the Browns Lane factory. Luckily damage was reasonably restricted, and with marvelous co-operation from the workforce and suppliers, normal production was resumed remarkably swiftly. Nine XKSS chassis were destroyed in the fire before they could be completed. In 2016 Jaguar announced that a small production run of nine "continuation" XKSS reproductions would be hand-built to the original specifications to complete the originally scheduled run of 25 cars.

The same near-disaster almost ruined the launch of a new sister for the 2.4 saloon. Logically, Jaguar had decided to fit the 3.4 engine in the saloon body, and this made a very sprightly sporting saloon. Maximum speed was 120 mph, and 60 mph could be reached in just 11.7 seconds. Outstanding performance for a sports saloon in 1957.