Contemporary records indicate that there were 76 'short nose' Ds. Five had XKC chassis numbers, respectively XKC 401 (the prototype) followed by 402-405 (this last car was never completed), while the sixth was the first to be stamped XKD (406). The Production versions started at 509. There was also apparently a glass-fibre experimental vehicle (544) that was supposedly scrapped. Many years later it reappeared with a conventional monocoque.
Sixteen of these cars became XKSS variants, actually unsold renumbered production D-types, and three more were destroyed in the Brown's Lane fire of February 1957 (565, 571 and 574). One car (543), used for display purposes at dealerships, was also destroyed in the fire but its remains sold on. Two more XKSSs were created by the factory in 1958 --- out of 533 for Pierre Chemin and out of 540 for hillclimb specialist Phil Scragg.
The 'long nose' cars numbered 11 in total: five in 1955 (504 to 508) and six in '56 (601 to 606). 604 was written off and scrapped after an accident at Silverstone in '56, while 602 was also written off, at Le Mans, but its remains were rebuilt into a new 603, which had also been crashed at Le Mans.
Four of these cars used Lucas injection: 601 at Sebring, 602 at Le Mans and 605 at Reims and Le Mans, all in 1956; the other was 606 at Le Mans in '57. (Early experiments were carried out by 504.)
Criticism of the D-type's inability to cope with bumpy, windy roads and tracks because of its live rear axle led to experiments with de Dion rear suspension designs. This principle was tried on the original prototype XKC 401 in 1955 and two 'long nose' cars, XKD 505 and 604. Despite suffering driveshaft coupling failures, 604 was raced at Silverstone in this form: it crashed and the de Dion unit was subsequently abandoned somewhere at the factory.
Another technical departure was the testing of a five-speed gearbox at Lindley in August 1956. This too suffered a design fault, causing it to jump out of third gear. But in any case, Jaguar had by then decided to pull out of racing, handing the flag to private teams, particularly Ecurie Ecosse.
The flat-out blind of the 1957 Monzanapolis race on the banked Italian circuit suited the D-type admirably, the Ecurie Ecosse cars of Jack Fairman, Jock Lawrence and Ninian Sanderson finishing fourth, fifth and sixth. As a direct result of this, it is reported that a D-type was tested at Indianapolis oval by roadster ace Pat O'Connor. He lapped at 131.965mph, only 7mph slower than the 1957 qualifying times, and stated that limited chassis changes, bigger tyres and a longer (!) stroke could give the car "a real good chance" in the 500.
In 1958, Ecurie Ecosse returned to Monza with its own hastily created offset Lister-Jaguar and D-type, but neither car fared well.
The destroked XK unit in all its forms was never a success. The 2.5-litre engine at Dundrod in 1954 was the basis for the 2.4 Mkl and developed 190bhp but was never used again in competition.
When the 3-litre limit came into being in 1958, Ecurie Ecosse had already built its own version based on an old MkVII block that gave 234bhp from 2954cc. The factory 2987cc engines gave 254bhp but were plagued by piston failures.
Jaguar tried again in 1959 with a different bore and stroke (85x88mm) based on the BSA Goldstar 'bike unit designed by Bill Nichols. This 2997cc engine developed between 258 and 294bhp in alloy-block form and with petrol injection for the one-off E2A at Le Mans in 1960. They, too, were fragile and tended to snap their titanium conrods.
One more version, developed by Ecosse's 'Wilkie' Wilkinson, was based on the 2.4-litre block but used a special Laystall crank. The engine's dimensions were square (86x86mm) and it gave 270bhp --- but only on a very high compression ratio that caused it to blow out its water under load; it ran at Le Mans 1959 in the Tojeiro and failed.
The first 3.8 was developed by Cunningham's Alfred Momo and fitted to 605 at Sebring in 1957.
The top speed of the D-type has always been a matter of conjecture. Quoted figures on the Mulsanne were always slightly suspect as various drivers and pundits have suggested that the cars were still accelerating at the measuring point. Masten Gregory recorded 178.8mph in Duncan Hamilton's 3.8 car at Le Mans in 1957, but Norman Dewis reckons his narrow-screen car reached 192mph in '55. Given that the full-width screen probably cost over 10mph, this might just be possible.
The highest officially recorded speed for a D-type was achieved by Thomas Rutherford of Massachusetts. His specially prepared 'short nose' had a narrow screen, wheel discs and tailpipes. Fitted with a 3.8-litre engine, it was clocked at 185.47mph at Bonneville in 1960.
Elsewhere, Pat Coundley, wife of D-type and Lister racer John, recorded an FTD of 161.278mph at the Antwerp Speed Trials in May 1964, despite heavy rain, to become Europe's fastest woman.