Produced from 1970 to 1981, the Avenger was significant as it was the first and last car to be developed by Rootes after the Chrysler takeover in 1967. Stylistically, the Avenger was undoubtedly very much in tune with its time; the American-influenced "Coke Bottle" waistline and semi-fastback rear-end being a contemporary styling cue, indeed the Avenger would be the first British car to be manufactured with a one piece plastic front grille. It was similar in appearance to the larger Ford Cortina Mark III (1970–1976), which was launched later in 1970. Originally manufactured by the former Rootes division of Chrysler Europe it was badged from 1976 onward as the Chrysler Avenger. Between 1979 and 1981 it was manufactured by PSA Peugeot Citroën and badged as the Talbot Avenger.

From an engineering perspective it was rather conventional, using a 4-cylinder all-iron overhead valve engine in 1250 or 1500 capacities driving a coil spring suspended live axle at the rear wheels. Unlike any previous Rootes design, there were no badge-engineered Humber Sunbeam or Singer versions in the UK market. The Avenger was immediately highly praised by the press for its good handling characteristics and generally good overall competence on the road and it was considered a significantly better car to drive than contemporaries like the Morris Marina.

Named to evoke memories of the Sunbeam Tiger, the Avenger Tiger concept began as a publicity exercise. Avenger Super (four-door) cars were modified by the Chrysler Competitions Centre under Des O'Dell and the Tiger model was launched in March 1972. Modifications included the 1500 GT engine with an improved cylinder head with enlarged valves, twin Weber carburettors and a compression ratio of 9.4:1. The engine now developed 92.5 bhp (69 kW) at 6,100 rpm. The suspension was also uprated, whilst brakes, rear axle, and gearbox are directly from the GT. Road test figures beat the rival Ford Escort Mexico, but fuel consumption was heavy.