Today DTW remembers Renault’s post-WW2 series of rear-engined cars.
The post-war worldwide success of the Volkswagen Beetle(1) encouraged manufacturers as diverse as Fiat, NSU, Renault, Rootes, Skoda, ZAZ and even General Motors to emulate its mechanical layout, with varying fortunes. In so doing, many appeared to miss the point that the Beetle was successful despite rather than because of its rear-engined layout.
A rear-engined design typically involves many compromises with regard to packaging for luggage space, engine accessibility and cooling, and handling and stability. The smaller the car, the less important these compromises are, but the layout becomes increasingly unviable as the design becomes larger and more powerful. Porsche spent the best part of sixty years engineering out the instability(2) caused by having a heavy weight mounted aft of the rear axle on the 911, while General Motors suffered huge reputational damage owing to claims of dangerous instability made about the rear-engined Mk1 Chevrolet Corvair.
During WW2, Renault was controlled by the occupying German forces and was under orders to build only military and commercial vehicles in support of the Third Reich’s war effort. Renault’s Director of Design, Fernand Picard, anticipated that, after the war, France would need a small and economical car to help remobilise the country. He led a small team that covertly developed what would become the 4CV.
There has been much debate as to what extent the mechanical layout of the rear-engined 4CV had been influenced by the VW Type 1. Renault was nationalised immediately after the war and its new chief executive, a fiercely patriotic former resistance fighter named Pierre Lefaucheux, was outraged by that suggestion, and even more outraged when the new French government asked Ferdinand Porsche to advise on getting the 4CV into production. Porsche received a hostile reception at Renault, then spent almost two years without trial in a French prison on unproven allegations of war crimes, allegedly at the behest of Lefaucheux.
In any event, the 4CV was unveiled in 1946 and entered production the following year. It was a rather pleasant looking small four-door, available in saloon and cabriolet versions. The latter was simply the saloon with a roll-back fabric roof. Later, a commercial version would be offered, although this was little more than a saloon with no rear seats and unglazed rear doors. The 4CV had a monocoque bodyshell and was 3.66 metres (12 ft) long.
Powered by a 760cc 17.5BHP inline-four engine mated to a three-speed gearbox, the car weighed just 620kg (1,370lbs) and was a sprightly enough performer to prove a bit tricky on wet roads, particularly with its light front end and highly geared steering, at just 2½ turns from lock to lock. Renault subsequently reduced the gearing to 4½ turns to reduce the risk of accidents.
Sales started slowly but picked up strongly as the French and European economies began to recover. The 4CV was exported widely and assembled from CKD kits in a number of overseas territories in order to avoid punitive import taxes. Total sales were 1,105,543 which made the 4CV the biggest selling French car to that date. It was nominally replaced by the Dauphine in 1956 but its lower price and specification allowed it to remain in production until 1961, when the FWD Renault 4 was launched.
As the post-war economic recovery gathered pace, Lefaucheux and Picard saw an opportunity to offer a larger and better appointed car than the 4CV. Development work began in 1951 on what would become the Dauphine. The exterior style was agreed at a relatively early stage in the process: recognisable prototypes were being road tested as early as 1952, some four years before the Dauphine’s launch.
Whatever the influence or otherwise of the VW Type 1 on the 4CV’s design, there is little doubt that the Dauphine was benchmarked directly against its German competitor. This led to the engine, carried over from the 4CV, being increased in capacity to 845cc to improve the car’s performance.
The car was officially launched at the Geneva Motor Show in March 1956. Although pre-launch press publicity had referred to it simply as the 5CV, it was given the name Dauphine in reference to its position as heir apparent to the (4CV’s) throne. The new model was 275mm (11”) longer than the 4CV and had a conventional ponton-style three-volume profile, albeit rounded off in a nod to aerodynamics. The monocoque design weighed 650kg (1,430lbs) an increase of just 30kg (66lbs) over its predecessor.
One unusual feature was a separate compartment for the spare wheel underneath the front boot, which was accessed via an external lid below the raised centre section of the front bumper. Another neat touch was the scallops in the rear doors that accommodated the engine air intake grilles ahead of the rear wheel arches. The scallops were in turn accommodated by sliding, rather than winding, windows in the rear doors.
The standard transmission was a three-speed manual gearbox carried over from the 4CV, although a push-button operated three-speed automatic(3) was offered as an option. The latter was thought to improve the Dauphine’s appeal to female drivers, as was a range of pastel colour choices. Later, a four-speed manual transmission was offered on the short-lived 1961 Ondine luxury version, and also on the more successful Gordini sporting variant, which had an engine tuned to produce 37bhp and was fitted with disc brakes all round from 1964.
There was a sting in the Dauphine’s tail; a function of its rear-engined layout, which placed 60% of the car’s weight over the rear wheels, coupled with rudimentary swing-axle rear suspension. This could cause an abrupt transition to oversteer when cornering at speed. Renault attempted to tame this tendency by fitting a front anti-roll bar and specifying low front tyre pressures, but it remained an issue, and a trap for the reckless or unwary.
The Dauphine’s other major weakness was corrosion. Its lightweight construction and inadequate rustproofing made it no match for some of the harsher climates to which it was exported. Early success in the US, where over 100,000 examples were sold in 1959, was quickly undermined by a reputation for extreme fragility. In this regard it compared unfavourably with the crude but tough VW Beetle, which retained its crown as leading US import.
The Dauphine was only produced in a single body style, but there were pretty convertible and coupé models built on the same platform and mechanical package called the Caravelle (or Floride until 1962 in markets other than the UK and USA). The Caravelle was designed by Pietro Frua at Ghia. It was launched in 1958 and sold for a decade. The Dauphine itself remained in production until 1967 and, like its predecessor, was exported widely. A total of 2,150,738 cars were sold over eleven years before it was replaced by the Renault 8.
(1) The VW Type 1 was itself a copy of the mechanical layout employed by the Czechoslovakian company Tatra since it produced the V570 prototype in 1931. Tatra actually launched legal action against VW for copyright infringement, but this was brought to an abrupt end by Germany’s invasion of Czechoslovakia in 1939. VW finally paid a modest DM 1m to Tatra in an out-of-court settlement in 1965.
(2) In layman’s terms, the problem is that the weight of the engine acts as a ‘pendulum’ at the rear end. If the driver enters a bend too fast, then lifts off, the rear tyres can lose grip, causing the rear end to break away, a phenomenon known as lift-off oversteer. In extremis, the car can leave the road backwards, with dangerous consequences.
(3) In reality, it was just an electromagnetically operated clutch, not a fully automatic transmission, but was similar to the system VW offered on the Beetle.