The Eldorado model was part of the Cadillac line from 1953 to 2002. The Cadillac Eldorado was the longest running American personal luxury car as it was the only one sold after the 1999 model year. Its main competitors included the Lincoln Mark Series and the lower-priced Buick Riviera.
Although cars bearing the name varied considerably in bodystyle and mechanical layout during this long period, the Eldorado models were always near the top of the Cadillac line. Nevertheless, and except for the Eldorado Brougham models of 1957–1960, the most expensive models were always the opulent, long wheel-based Series 75 sedans and limousines, not the Eldorado.
The Eldorado was radically redesigned in 1967. Intended for the burgeoning personal luxury car market, it was a "personal" Cadillac sharing the E-body with the Oldsmobile Toronado and Buick Riviera, which had been introduced the previous year. Cadillac adopted the Toronado's Unified Powerplant Package and front-wheel drive. (Contrary to popular belief, the similar Buick Riviera did not use the front-wheel drive setup until 1979.) The Eldorado used a standard Cadillac 429 V8 with a modified Turbo-Hydramatic automatic transmission (THM425, based on the Turbo-Hydramatic 400) with the torque converter mounted next to the planetary gearbox, driving it through a metal chain.
Despite sharing underpinnings with the Toronado, the Eldorado's crisp styling, initiated by GM styling chief Bill Mitchell, was distinctive and unique, appearing more angular than the rounded Toronado. Performance was 0–60 mph (0–96 km/h) in less than nine seconds and a top speed of 120 mph (192 km/h). Roadability and handling were highly praised by contemporary reviews, and its sales, 17,930 units, helped give Cadillac its best year ever. Disc brakes were optional in 1967 and became standard in 1968. The new Eldorado was a great departure from the previous generation, which had become little more than a dressed-up version of Cadillac's Series 62. Sales were excellent despite high list prices.
In 1968, the Eldorado gained slight exterior changes to comply with new federal safety and emissions legislation, and as with the rest of the Cadillac lineup, a new 472 cu in (7.7 l) V8 rated at 375 hp (280 kW) (SAE gross). In 1969 it lost its hidden headlamps and picked up as options a halo vinyl roof and later in the model year a power sunroof option. For the 1970 model year, the Eldorado introduced the new 500 cu in (8.2 l) V8 engine, the largest-ever production V8, rated SAE gross 400 hp (298 kW) and 550 ft·lbf (746 N·m) in 1970, that would be an Eldorado exclusive until it became standard on all full size Cadillacs in the 1975 model year.