The Mark VII chassis came from the Jaguar Mark V and the wheelbase remained the same at 10 feet (3,048.0 mm). The new model's body looked more streamlined, with integrated headlights and mudguards, a two-piece windscreen, and longer rear overhang. As on the Mark V, the rear wheels were partially covered by removable spats.
When the car was being developed Jaguar thought it would find most of its customers overseas, mainly because UK car tax at that time penalised buyers of larger-engined cars. However it went into production just as Britain's postwar economic austerity began to ease, and in 1951 the car's enthusiastic reception in both the British and American markets prompted Jaguar to relocate production to larger premises, at the Browns Lane plant, which had been built for wartime production as a shadow factory and was now available for immediate use.
The published performance figures for the Mark VII were based on the standard 8:1 compression ratio, but as this was unsuitable for the UK market's low-octane Pool petrol a 7:1 engine was optional. British motoring magazines tested the car's performance with the higher compression ratio, using the Ostend to Brussels autoroute in Belgium, where 80 octane fuel was available. A Mark VII tested by The Motor in 1952 had a top speed of 101 mph (163 km/h), accelerated from 0–60 mph (97 km/h) in 13.7 seconds and returned 17.6 miles per imperial gallon (16.1 L/100 km; 14.7 mpg‑US). The test car cost £1693 including taxes.
In 1952 the Mark VII became the first Jaguar to be offered with automatic transmission.
By the time the model was upgraded to M specification in 1954, 20,908 had been produced.
Mark VII M 1954–1956
The Mark VII M was launched at the British International Motor Show in October 1954. Although the engine continued with the same capacity and 8:1 compression ratio, it was uprated to 190 bhp (141.7 kW), giving the car a claimed top speed of 104 mph (167 km/h).
The four-speed manual gearbox was standard, while the Borg Warner automatic, hitherto available only on exported Mark VIIs, now became optional for British buyers.
Jaguar Mark VII M
Distinguishing the Mark VII M from its predecessor, circular grilles over the horns were installed below the headlights in place of the former integrated auxiliary lamps, which were moved slightly further apart and mounted on the bumper. Both bumpers now wrapped further around the sides of the car.
In 1956, with the advent of the Suez Crisis Britain anticipated fuel rationing, and bubble cars appeared on the streets. Jaguar switched focus to their smaller saloons (the Mark I 2.4 had been introduced in 1955), and neither the Mark VII M nor any of its increasingly powerful but fuel-thirsty successors would match the production volumes of the original Jaguar Mark VII. Nevertheless, before it was superseded by the Mark VIII, the Mark VII M achieved 10,061 sales during its two-year production run.
Racing and rallying
Both variants of the Mark VII won race victories, and an M version won a Monte Carlo Rally.
In 1954 Jaguar built a lightweight Mark VII M which, although intended for racing, never participated in contemporary events. Road-registered KRW 621, it had magnesium body panels, D-type engine, Dunlop disc brakes and modified suspension.