In 1971, the redesigned full-size B-body would be the largest full-size car ever offered by GM. However, the 1970s marked the impact of the 1973 energy crisis. Gasoline prices doubled between 1973 and 1979. Industry car sales plummeted 20 percent between 1973 and 1974, and for the first time in recent history, annual passenger car travel in the U.S. actually declined.
The Impala’s sales dropped to 176,376 units in 1975, the weakest since its introduction in 1958. In spite of the large size of these cars, an Econominder gauge package was offered on 1975 and 1976 models to keep track of gas mileage. Station wagons replaced the swinging tailgate with an unusual design where the back window retracted into the roof, which was abandoned on the subsequent redesign.
Starting in 1968, two coupe models were offered on Impalas, the “Sport Coupe” was the lower-priced hardtop coupe design, shared with other GM “B” body hardtop coupes, and the formal-roof “Custom Coupe” which was the Caprice Coupe body in Impala trim. Sport Coupe models were discontinued after 1975, leaving the Custom Coupe, with its wide “B” pillar and fixed rear window, the only 2-door Impala available in 1976. This body style was actually introduced for the 1974 model year, a precursor to Detroit’s complete abandonment of pillarless body styles before the end of the Seventies.
The 1972 model introduced a “gaping” grille which extended below the bumper. The large size was partly because of federal bumper rules which required 5-mile-per-hour (8.0 km/h) impact protection beginning in 1973, and the rear in 1974. 1974 Chevrolet Impala 4-door Sedan with original factory paint
Powertrains consisted of V8 engines mostly (the 250 inline six was standard through 72, then the 2bbl 350 was standard from 73-76), offered with 350 cubic inches (5.7 L), 400 cubic inches (6.6 L), 402 cubic inches (6.6 L) (through 72) or 454 cubic inches (7.4 L); however, the long-familiar OHV six-cylinder Turbo Thrift engine continued to be standard on two-door hardtop coupe and four-door pillared sedan models through the end of the 1972 model year. Beginning in 1972, all engines were designed to run on unleaded gasoline. Catalytic converters were introduced in 1975. High Energy Ignition, or HEI, debuted on the 75 models as well, although it is said HEI was installed on some 1974 cars. The Impala convertible model was dropped after 1972, and continued as a Caprice until 1975.
Several new options were offered for the first time in 1975. In addition to the Econominder gauge package, new options included intermittent wipers and a divided 50-50 bench seat (with a choice of sport cloth or vinyl trim). Also in 1975, the dashboard, radio and climate control graphics were revised; the speedometer read up to 100 miles per hour (160 km/h), and had smaller numbers for kilometers per hour.
Although the “Super Sport” model was long since discontinued, two special models were offered:
- A “Spirit of America” package. Offered in 1974 on Sport Coupe models, this was primarily a trim package featuring special white body paint, a white vinyl top, sports-styled dual remote outside rear view mirrors, special wheel covers, optional rally rims (sourced from the Chevrolet C10 truck, painted white), a vinyl body side molding insert, and pin striping and interior trim in either red or blue. The interior trim also included color-keyed seat belts and floor mats. Special fender badges (along with one on the dashboard) announced the package to passengers or passers-by.
- A “Landau” model, for 1975-1976 models (and carried over into the late 1970s and 1980s). Like the “Spirit of America” package, this was primarily an appearance package. The model featured a choice of special paint colors, sports-styled dual remote outside rearview mirrors, color-keyed wheel covers, a landau vinyl roof (with chrome band across the roof), a vinyl bodyside molding insert, and pinstriping. Inside there were color-keyed seat belts and floormats. Fender and dashboard emblems rounded out the package.