lightweight materials. The resulting body shape resulted in a very low 0.239 drag coefficient. The project was sponsored by the French government. Initial range The Renault 18 went into production at Renault's Flins factory in France in December 1977. It was presented at the Geneva Salon in March 1978, with marketing and sales starting the following month. Initially, the R18 was only available as a four-door saloon, in TL, GTL, TS and GTS trim variations. The TL and GTL were powered by the 1397 cc Renault Cléon petrol engine (which was developed from the 1289 cc engine from the Renault 12), which produced . Both models had a four-speed gearbox. The TS and GTS were powered by the 1647 cc A-Type engine (which was the same as used in the Renault 17 TS) but without the fuel injection, which lowered the output to . The TS had a four-speed manual gearbox, while the GTS had a 5-speed manual gearbox, with optional 3-speed electronic automatic transmission available for both models. The automatic versions of the TS and GTS models were called the TS Automatic and GTS Automatic to distinguish them from their manual transmission counterparts. Beginning in 1978, the Renault 18 was also assembled in Romania under the name Dacia 18. Fewer than 100 cars were built by Dacia, mainly for the government. It had been intended as a replacement for the Dacia 1300, a model derived from and based on the Renault 12, but the license and production between Dacia and Renault ended in 1979 and the model was dropped. The 18 was Renault's first car to use the 1.4 L Cléon engine in the medium-size car sector. The Renault 18 also used three-stud wheels (similar to those of the Citroën 2CV), rather than the four- or five-stud wheels common on most of its contemporaries. In 1980 Turbo and Diesel R18 models came fitted with four-stud wheels (necessitated by using suspension parts and wheels from the larger R20 and Fuego), with all versions using four-stud wheels from the 1983 facelift onwards. Timeline Deliveries began early in April 1978 and sales in the United Kingdom began just before Christmas. On the British market, it was designed to compete with the market-leading Ford Cortina, Morris Marina, Vauxhall Cavalier and Chrysler Alpine – with all of these cars except the Alpine featuring rear-wheel drive. It was initially hugely successful on the UK market,