IN THIS FEATURE Early days Popular personal luxury The Squarebird Projectile styling Growing again Ugly duckling Aerodynamic phase Temporary retirement New Thunderbird

The 1983 Thunderbird was far more radical than its predecessor. Introducing an angular, aerodynamic style to become common in Fords and the wider industry, it was also much more technologically complex; it featured a new electronic engine control module developed by Ford's F1 racing programme. Proven on the track as well as the road - the Thunderbird NASCAR racer won over 150 races, including four victories at the Daytona 500 - this model was considered worthy of the Thunderbird name again. It had also adapted to move with the times: a four-cylinder, turbocharged 2.3-litre engine was offered, in conjunction with a five-speed manual gearbox and tauter suspension. The Turbo Coupe was said to be the best-handling and best-performing Thunderbird yet, though the 200cu-in six and 302 cu-in V8 continued as well. Thunderbird sales nearly tripled, reaching the 122,000 mark again, and the platform also formed the basis of the Lincoln Mark VII luxury coupe (1984).

1989 Super Coupe had 210bhp

A minor restyle in 1985 brought a new grille, larger wheels and a retouched interior, but sales were declining. 1987 saw the turbo engine replaced by the new intercooled turbo unit from the Mustang SVO (190bhp with the manual gearbox, 150bhp with the auto) and the adoption of a new grille-less front end - rather similar to that of the European Sierra of the time. Sales picked up again in '88 to around 147,000, and a year later, a revised model with all-independent suspension was launched. The range-topping SC version was supercharged for 210bhp, putting some clear ground between the Thunderbird range and the all-new Probe coupe also launched that year. The market was changing, however; the American economy was sluggish, car sales were falling overall, the domestic manufacturers were increasingly losing out to importers such as Toyota and Honda, and fashions were changing as those who were still buying cars began to opt more for 4x4 sport-utility vehicles and pick-ups trucks, even in relatively urban areas. And crucially, the Thunderbird was just no longer competitive.