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 4-speed gearbox. The TS and GTS were powered by the 1647 cc A Series 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 4-speed gearbox, while the GTS had a 5-speed 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.
The 18 was Renault's first car to use the 1.4 L Cléon engine in the medium-size car sector. A point of interest with the 18 was its wheels: unusually for a car of such relatively large size, it utilized 3-stud wheels (similar to that of the Citroën 2CV), rather than the 4- or even 5-stud wheels of most of its competitors. The 18 gained 4-stud wheels in 1980.
By the late 1970s, European production of the Renault 12 was being gradually wound down, followed by the arrival of the estate versions of the Renault 18 on 1 March 1979. The R18 Estate ("Break" in French-speaking countries) was only available in TL and TS model variations. They were mechanically identical to their saloon counterparts except the rear suspension used in the estates was more like that in the bigger Renault 20 and Renault 30. As for equipment specifications, the estates were identical to the saloons, except the TS estate additionally featured shock-absorbent bumpers, door mouldings, and front seat head restraints from the 18 GTL saloon. The estate proved almost as popular as the saloon.
The Renault 18 estate was also sold (as the "Sportwagon") through American Motors (AMC) in the North American market from 1981 to 1986, and the saloon in 1981–82 as the Renault 18i. However, it was not a success. It was replaced by the Renault 21's North American equivalent, the Eagle Medallion.
The 18 was discontinued in Europe in 1986, but continued in production until 1993 in South America. In Argentina and Colombia, there were other versions too, namely the TX and GTX. The TX being the initial 1982 model, featuring the first 2.0 L powerplant fitted to a production 18 worldwide (there was a need for a powerful car to replace the Renault Torino luxury-sports range). There was also the GTX-II, featuring a basic on-board computer that displayed fuel consumption, etc. It was available with 1.6 L (TL), 2.0 L and 2.2 L engines. There was a special edition of the 18 with two-tone paint (black top and light grey bottom) called the American (later updated with central locking and other items, which was named the American 2).
| Index Name | Production Years | Engine Size | Notes | |
|---|---|---|---|---|
| Renault 18 TL | 1978–1986 | 1397 cc | Touring Luxe specification includes: Two-speed wipers Intermittent screen wipe Electric screen washers Volt meter Engine coolant temperature gauge Fuel gauge Six-figure mileage recorder Trip recorder Handbrake warning light Defective front brake discs warning light Day/night position for interior rear view mirror Rheostat for adjusting brightness of dashboard lights Illuminated ashtray, heater panel, boot and glove box Heated rear screen Anti-dazzle headlight adjustment Adjustment for direction of headlight beam Cigarette lighter Drivers side sun visor Passengers side sun visor Vanity mirror in passengers side sun visor Full carpeting Cloth upholstery Front armrests with grab handles Rear armrests Ashtrays in the rear doors Childproof rear door locks Passengers side interior courtesy light Front door pockets Center console incorporating coin tray Reclining front seats Loudspeakers in front doors. | |
| Renault 18 GTL | 1978–1986 | 1397 cc (1978-1982) 1647 cc (1982-1986) | Grand Touring Luxe has specification of TL plus: Foam-filled steering wheel H4 iodine headlights Quartz clock Velour upholstery Styled wheels Drivers side interior courtesy light Map reading light for front seat passenger Remote-adjustable driver's side door mirror Rear fog lights Headlight wash/wipe system Pre-installation radio equipment Shock absorbent bumpers Adjustable front seat head restraints Black rubber protective side mouldings. | |
| Renault 18 LS | 1979–1981 | 1647 cc | Luxe Super has specification of TL. | |
| Renault 18 TS | 1978–1982 | 1647 cc | Touring Special has specification of TL, plus: Foam-filled steering wheel H4 iodine headlights Quartz clock Velour upholstery Styled wheels Drivers side interior courtesy light Map reading light for front seat passenger. | |
| Renault 18 GTS | 1978–1983 | 1647 cc | Grand Touring Special has specification of GTL, plus: Electric front windows Central locking | |
| Renault 18 TD | 1980–1985 | 2068 cc Diesel | Touring Diesel has specification of TS. | |
| Renault 18 GTD | 1980–1986 | 2068 cc Diesel | Grand Touring Diesel has specification of GTS. | |