Eighth generation (1979–1985)
A new, trimmer Eldorado was introduced for 1979, for the first time sharing its chassis with both the Buick Riviera and Oldsmobile Toronado. Smaller, more fuel efficient 350 and 368 in³ (5.7 and 6.0 L) V8’s replaced the 500 and 425 in³ (8.2 and 7.0 L) engines. A diesel 350 was available as an option.
In 1980, the gas 350 was replaced with the 368 except in California, where the Oldsmobile 350 was used. In both the 1980 Seville and Eldorado (which shared frames) the 368s came with DEFI (later known as throttle body injection when it was later used with other GM corporate engines), whereas in the larger RWD Cadillacs it came only with a 4-barrel Quadrajet carburetor.Independent rear suspension was adopted, helping retain rear-seat and trunk room in the smaller body. The most notable styling touch was an extreme notchback roofline. The Eldorado Biarritz model resurrected the stainless-steel roof concept from the first Brougham. The Eldorado featured frameless door glass, and the rear quarter windows re-appeared as they did before 1971, without a thick “B” pillar. The cars were not true hardtops, as the rear quarter windows were fixed. Sales set a new record at 67,436.
For 1981, Cadillac offered the V8-6-4 variable displacement variant of the 368 engine, which was designed to deactivate some cylinders when full power was not needed, helping meet GM’s government fuel economy (“CAFE”) averages. It was a reduced bore version of the 1968 model-year 472, sharing that engine’s stroke and also that of the model-year 1977–1979 425. The engine itself was extremely rugged and durable, but its complex electronics were the source of customer complaints.
1981 was the first year electronic “digital” instrumentation was an available option. In addition to the digital electronic climate control that was standard on all Eldorados, the standard analog speedometer and fuel gauges could be replaced with digital displays with features displaying gallons of remaining fuel and approximate range.
Another engine was introduced for 1982. The 4.1 L HT-4100 was an in-house design that mated cast-iron heads to an aluminum block. Some HT-4100s were replaced under warranty.
From 1982 through 1985, Cadillac offered an ‘Eldorado Touring Coupe’, with heavier duty suspension, alloy wheels, blackwall tires, minimal exterior ornamentation and limited paint colors. These were marketed as ‘driver’s cars’ and included bucket seats and a center console.
In 1984, Cadillac also introduced a convertible version of Eldorado Biarritz. It was 200 pounds (91 kg) heavier featuring the same interior as other Biarritz versions. The model year of 1985 was the last year for the ASC, Inc., aftermarket conversion Eldorado convertible. Total sales set an all-time record of 77,806, accounting for about 26% of all Cadillacs sold.
Prior to the ‘official’ 1984 and 1985 Eldorado convertibles marketed by Cadillac, some 1979-83 Eldorados were made intocoach convertibles by independent coachbuilders e.g. American Sunroof Corporation, Custom Coach (Lima, Ohio – this coachbuilder turned a few 1977 and 1978 Eldorados into convertibles), Hess & Eisenhardt. The same coachbuilders also converted the Oldsmobile Toronado and Buick Riviera into a ragtop.
Late in the 1985 model year, an optional ‘Commemorative Edition’ package was announced, in honor of the last year of production for this version of the Eldorado. Exclusive features included gold-tone script and tail-lamp emblems, specific sail panel badges, gold-background wheel center caps, and a “Commemorative Edition” badge on the steering wheel horn pad. Leather upholstery (available in Dark Blue or White, or a two-tone with Dark Blue and White) was included in the package, along with a Dark Blue dashboard and carpeting. Exterior colors were Cotillion White or Commodore Blue.