Prototyping
Internally known as "Project 109" the Dauphine's engineering began in 1949 with engineers Fernand Picardy, Robert Barthaud and Jacques Ousset managing the project.
A 1951 survey conducted by Renault indicated design parameters of a car with a top speed of 110 km/h (68 mph), seating for four passengers and fuel consumption of less than 7 L/100 km (40 mpg; 34 mpg). The survey indicated that women held stronger opinions about a car's colors than about the car itself (See below, Marrot at Renault).
Engineers spent the next five years developing the Dauphine. Within the first year, designers had created a ⅛th scale clay model, studied the model's aerodynamics, built a full scale clay model, studied wood interior mockups of the seating, instrument panel, and steering column — and built the first prototype in metal.
Having largely finalized the exterior design, testing of the prototype began at Renault's facilities at Lardy, France — by secrecy of night, on July 24, 1952.
Using new laboratories and new specially designed tracks, engineers measured maximum speed, acceleration, braking and fuel consumption as well as handling, heating and ventilation, ride, noise levels — and parts durability. Engineers tested parts by subjecting them to twisting and vibration stresses, and then redesigning the parts for manufacture.
By August 1953, head engineer Picardy had an almond green prototype delivered to Madrid for dry condition testing — ultimately experiencing only five flat tires and a generator failure after 2,200 km (1,400 mi). Subsequently, Lefaucheux ordered engineers to test a Dauphine prototype directly against a Volkswagen Beetle. The engineers determined that noise levels were too high, interior ventilation and door sealing were inadequate and most importantly, the engine capacity was insufficient at only four CV (748 cc). The four-cylinder engine was redesigned to increase its capacity to 845 cc by increasing the bore to 58 mm — giving the car a new informal designation, the 5CV. By 1954, a second series of prototypes incorporated updates, using the older prototypes for crash testing.
Lefaucheux followed the testing carefully — often meeting with his engineers for night testing to ensure secrecy — but did not live to see the Dauphine enter production. He was killed in an automobile accident on February 11, 1955, when he lost control of his Renault Frégate on an icy road and was struck on the head — by his unsecured luggage as the car rolled over. The Flins factory was renamed in his honor, and he was succeeded on the project by Pierre Dreyfus. A monument in Lefaucheux's memory is erected at the Saint-Dizier highway exit, Haute-Marne 52100.
By the end of testing, drivers had road tested prototypes in real world conditions including dry weather and dusty condition testing in Madrid, engine testing in Bayonne, cold testing at the Arctic Circle in Norway, suspension testing in Sicily, weatherseal testing in then-Yugoslavia — with more than two-million kilometers of road and track testing.
In December 1955, Pierre Bonin (director of the Flins Renault Factory) and Fernand Picard presented the first example to leave the factory to Pierre Dreyfus, who'd taken over the project after the death of Pierre Lefaucheux.
Read more about this topic: Renault Dauphine