The 1963 Hillman Imp was Rootes’ answer to BMC’s Mini, but a latecomer to the market and, ultimately, a commercial failure. We conclude its story.
Autocar magazine had been given early access to an Imp De Luxe for testing and published its road test just a day after launch. The price including tax was £532, a £24 premium over the standard version. The reviewer praised the new engine’s smoothness, quietness and willingness to rev. They noted that, despite an unusually high 10:1 compression ratio, it ran without any trace of ‘pinking’ or ‘run-on’ on Premium(1) grade petrol.
The recommended top speed of 70mph (113km/h) was easily exceeded, and a maximum of 83mph (134km/h) was recorded one-way. The 0 to 60mph (97km/h) time was measured at 23.7 seconds. Fuel consumption over the course of the road test was 38.1mpg (7.4 L/100km).
No coolant temperature gauge was fitted, and the reviewer had to add a pint (0.57L) of water to the empty header tank every 300 miles (485km). This was a portent of a significant problem with the Imp that would emerge later. Two unusual features were a pneumatic throttle linkage and an automatic choke. The former was quite sensitive and took some getting used to, but the latter performed perfectly during the test. The gearchange was light and precise, with an unbeatable synchromesh. The clutch was smooth and progressive, although the articulation of the pedal was somewhat awkward.
The unusually wide differential in recommended tyre pressures, 15 p.s.i. (1.03 Bar) front and 30 p.s.i. (2.07 Bar) rear, and positive front wheel camber counteracted the rear-biased weight distribution, and the Imp tended to understeer when pushed hard, a characteristic described as “fail safe” by the reviewer. Directional stability was better than usually found with rear-engined cars, aided by precise rack and pinion steering. The ride was generally good but became unsettled over ‘washboard’ ridged road surfaces or deep potholes, when significant scuttle shake was experienced.
Overall, the reviewer rated the car highly and praised its roominess and its “superb little engine and transmission”. So, a positive reception at launch for the Imp, but trouble would soon follow. Despite its protracted eight-year development period, the Imp was launched with a number of features added late in the process and insufficiently tested. Issues with these features would soon damage its reputation.
Moreover, by 1963, the fashion for rear-engined small cars, so prevalent in the mid-1950’s when the project had commenced, was in retreat. BMC’s revolutionary transverse-engined FWD Mini had shown the way forward, although other manufacturers were initially slow to react. Fiat dipped a cautious toe in the water with the 1964 Autobianchi Primula, but it would be another five years before the parent marque would commit to the layout with the 1969 launch of the Fiat 128.
Notwithstanding its arguably outdated layout, the Imp had many positive qualities and sales started strongly, with around 33,000 finding buyers in the eight months from launch to the end of 1963, followed by another 50,000 in 1964. By the end of that year, however, the car was developing a reputation for unreliability.
Autocar’s launch road test of the Imp had noted its prodigious thirst for engine coolant. Insufficient airflow to a small rear-mounted radiator and an inadequate water pump caused the engine to run hot. The absence of a temperature gauge, or even a warning light, meant that this issue was often overlooked by drivers, sometimes with catastrophic results. The all-aluminium engine could suffer a warped cylinder head and blown head gasket, or even a complete seizure.
Other problems were experienced with the automatic choke and pneumatic throttle linkage. The resulting damage to the Imp’s reputation caused a fall in sales in 1965 to under 43,000 units. This was worrying for Rootes so early in the model’s life, especially after the company had widened the range by introducing an upmarket version called the Singer Chamois in late 1964.
The cost of developing and launching the Imp, together with the considerable investment in the new Linwood plant, had placed Rootes’ finances under considerable strain. This made the company receptive to an approach from Chrysler Corporation and, in June 1964, the US automaker bought 30% of the company’s ordinary shares and 50% of non-voting preference shares, leaving control still in the hands of the Rootes board and senior management(2).
Chrysler was allegedly the driving force behind an interesting but stillborn 1964 proposal for a four-door ‘Imp’. This was little more than a Simca 1000 with lightly modified bodywork. This proposal was seen as a means of extending the Imp range for a minimal investment.
Rootes decided that a relaunch was needed to address the Imp’s issues. A Mk2 version was unveiled in September 1965, with a raft of improvements to address the problems identified. These included a new water pump with modified seals, a larger cooling fan and a new head gasket, a conventional cable throttle linkage(3) and a manual choke. Other improvements included two steel struts behind the dashboard to reduce scuttle shake on rough roads and a rear undertray to protect the engine from road dirt. The inlet and exhaust ports in the cylinder head were also enlarged slightly. No improvement in performance was claimed for the latter change, but it ensured better consistency in engine build and power output. These mechanical changes were accompanied by some internal and external trim embellishments.
At the same time, the Imp range was rejigged. The basic model was dropped and a new Super version introduced. A van version, with new bodywork aft of the B-pillars, was launched under Rootes’ Commer commercial vehicle marque.
The package of improvements was comprehensive, but the Imp struggled to recover from the reputational damage caused by earlier issues. The situation was complicated by the fact that labour relations at the Linwood factory were poor, making it difficult to implement changes, and build quality remained variable.
A twin-carburettor version of the Imp was launched in October 1966 as the Sunbeam Sport and the same setup was offered on the Chamois. The next significant addition to the range was the Hillman Californian in January 1967. This was a coupé version of the Imp. The body below the DLO was unchanged but the car was given a more sloping rear screen, which was no longer inset between the C-pillars and did not open. The car was given more upmarket trimmings. A coupé version of the Singer Chamois followed in April, which was not meaningfully different to the Californian. More significant was the Hillman Husky, a version of the Commer Imp van with rear side windows and a rear seat, to create a makeshift estate car.
An oddity of the Imp up to 1967 was the pronounced positive camber of the front wheels. This means that the wheels sat, not at right angles to the road surface, but sloping outwards at the top. Together with the low 15 p.s.i. (1.03 Bar) front tyre pressures, this was intended to reduce front wheel grip and counteract the tendency of the car to oversteer because of the rearward bias of its weight distribution. From mid-1967, the suspension was adjusted to correct this, resulting in a more normal appearance and reduced tendency to understeer.
In October 1967, Rootes launched the upmarket Sunbeam Stiletto(4). This was based on the Californian but was distinguished by a smart twin-headlamp front end for which the Imp’s castellated bonnet always seemed to be designed. Rootes was now offering saloon, coupé estate and van versions under four different marque names, but this had little if any positive impact on sales.
Chrysler effectively took control of Rootes in 1968 and there followed a further round of mainly cosmetic revisions to the range in October of that year, including a new interior, seats and dashboard. Cars with these revisions were informally referred to as Mk3, but never officially carried that designation. The Commer marque was discontinued and the van was rebranded Hillman. In April 1970, the Singer models were dropped, followed by the Husky estate and van in July.
The remaining models limped on without meaningful further development and with little promotion until production ended in March 1976. The Imp’s engine, in enlarged 928cc form, would however again see service in the 1977 Chrysler Sunbeam, a stop-gap supermini based on a cut down Avenger floorpan.
Over thirteen years on the market, total sales of the Imp and its derivatives amounted to just under half a million units. After its early reliability issues were addressed, it was a pleasant and amiable small car, but it was, in hindsight, too late to market and its reputation never recovered from the early problems. Together with the financial and management burden of the troublesome Linwood plant, the failure of the Imp was the major reason for the demise of the Rootes Group as an independent UK motor manufacturer.
(1) Also known as four-star (98 Octane rating) petrol. There was also available a ‘Super’ five-star (101 Octane rating) petrol, which would normally be used in high compression ratio engines.
(2) Sadly, William (Lord) Rootes passed away on 12th December 1964.
(3) A retrospective modification was also offered for the pneumatic throttle linkage that resolved the problems with it.
(4) The name referred not to a style of women’s shoe, but to the word’s earlier meaning, a slim-bladed dagger. This connected the car to the larger Sunbeam Rapier coupé.
(1) My thanks to fellow DTW contributor, Robertas Parazitas, for his insights and contributions to this piece.
(2) Intrepid British auto journalist Archie Vicar also road-tested the Imp. His no-holds-barred report may be found here.