The 850 family included several body styles sharing core technical components: At the time of their introduction into the United States the Sedan, Coupé and Spider were marketed with a reduced capacity, high compression 817 cc (50 cu in) engine in order to beat US emissions regulations at the time which applied only to engines equal to or larger than 50 cubic inches.

In order to separate the sportier variants Coupé and Spider from the basic version, apart from the increase of engine performance, the equipment was also extended and adapted to the higher expectations.

In 1968, Fiat revised the successful Spider and Coupé again and gave them an even stronger engine with 903 cc and 52 hp (38 kW).

The headlamps were moved forward slightly and the glass covers were eliminated giving the car a "frog-eye" look, and the original flush front turn indicators were replaced with units hung below the bumper.

The establishment of the European Economic Community had gradually decreased Germany's protective tariffs, from 90 percent in 1957 to none at all from July 1968, and thus there was no longer any reason to assemble Fiats in Heilbronn.

[12] In 1967, Road & Track called the Fiat 850 coupé "one of the handsomest, best-balanced designs ever seen on a small car".

[15][16] Italian coachbuilder designed and built a small sports car with fastback coupé body based on the 850, the 1968 Francis Lombardi Grand Prix.

Introduced in 1967, it featured retro styling with a mock upright radiator grille, separate wings and headlights, and running boards.