General Motors developed a system of sharing body panels between models of its different makes, but the Ninety-Eight broke ranks several times with this system. Its second body makeover did not share body panels with the other senior makes, Buick and Cadillac. It did not even have its model-changeover synchronized with the same year as the Eighty-Eight in the mid-1950s.
Occasionally additional nomenclature was used with the name, such as L/S and Holiday, and the 98 Regency badge would become increasingly common in the later years of the model. The 98 shared its bodyshell with the Buick Electra. As it was the top-line Oldsmobile, the series had the most technologically advanced items available, such as Twilight Sentinel (a feature that automatically turned the headlights on and off via a timer, as controlled by the driver), and the highest-grade interior and exterior trim.
First generation (1941–1947)
Naming standards were in flux at Oldsmobile during the late 1930s and 1940s. From 1932 through 1938 Oldsmobile had two series: "F" and "L". Series F came with a straight-6 engine and Series L came with a larger body and a straight-8 engine. Series F was renamed Series 60 in 1939 and Series L was replaced with the Series 70 and 80, with the Series 70 and 80 being powered by the straight-6 and the straight-8 respectively. In 1940 a larger body was introduced and it alone was powered by the straight-8. In order to differentiate it from the previous year's Series 80 it was named Series 90 (there was no Series 80 that year).
The series were also given names for the first time that year with the Series 60, 70 and 90 being called the Special, Dynamic and Custom Cruiser respectively. In 1941 both engines were offered on each series so to differentiate between the two the second digit was used to denote the number of cylinders, so the Custom Cruiser 90 was replaced with the Custom Cruiser 96 and 98. In 1942 Oldsmobile dropped the six cylinder Series 90 model leaving only the Custom Cruiser 98. An electric clock was standard in 1947.
Second generation (1948–1953)
With the introduction of new postwar syling in 1948 the Custom Cruiser 98 was renamed the Futuramic 98. The following year the new styling was joined by a new engine, the now famous Rocket V8. In February 1949, several months into the model year, General Motors introduced three highly styled "hardtop convertible" coupes, the first of their type to be offered on a regular production basis (Chrysler had made seven prototype Town and Country hardtops in 1947).
The Oldsmobile version, called Holiday, was exclusive to the 98 series that year. Available in four special Holiday colors, as well as four two-tone combinations, it was priced the same as the convertible, and was similarly equipped, with hydraulically operated windows and seat. In 1950, for one year only, Oldsmobile added a 4-door fastback to the lineup which they called Town Sedan. Also in 1950, Oldsmobile stopped naming the 98 series and so from then through 1996 it was simply known as the Oldsmobile 98. In 1953, a padded safety dash became optional on the 98 and standard on the 98 Fiesta.
Third generation (1954–1956)
In 1954, all Oldsmobile cars were redesinged. The 98 got the safety padded dash as standard.
In 1955, the air conditioning unit was moved to the engine bay instead of the trunk. The turning circle was 43ft.
The 1956, 98 had a 126 in (3,200 mm) wheelbase. It used a 324 in³ Rocket V8. The parking brake was now a foot pedal.
Fourth generation (1957-1958)
In 1957, Oldsmobile added a safety recessed steering wheel. The 98 was renames Starfire 98. Power windows were standard. Front leg room was 43.8 inches.
In 1958, Oldsmobile added air suspension as an option. Also new was a speed warning device.
That engine was replaced by a 371 in³ engine for 1957 until the 371 was dropped in 1961
Fifth generation (1959–1960)
In 1959, the Oldsmobile line-up was redesinged. However, unlike other GM makes(such as Chevrolet and Cadillac) Oldsmobile continued to use a full perimeter frame, instead of the GM X-frame.
In 1960, an anti spin rear axle was optional.
The 394, the largest first-generation Rocket V8, was used from 1959 until 1964.
Sixth generation (1961–1964)
For 1961 only, it was renamed Classic 98; nevertheless, "most factory literature refers to the line as the Ninety-Eight." Malcolm X owned a 1963 Oldsmobile 98—black, 4 door, hardtop—and it can be seen in the lobby of the Malcolm X College on the south side of Chicago.
Seventh generation (1965–1970)
The 1965 Ninety-Eight received an all-new bodyshell along with other full-sized Oldsmobiles but retained a larger C-body shared with Cadillac in contrast with the B-body used in the Oldsmobile 88. The Ninety-Eight featured many of the lines found on 88s but with more squared off styling. Also new for 1965 was the Ninety-Eight Luxury Sedan, which featured an even more luxurious interior along with more standard amenities than the regular Ninety-Eight models such as power windows and seats. Most 98 LS's also had vinyl roofs, which were offered only in black that year. A new three-speed Turbo Hydra-Matic automatic transmission with torque converter replaced the Roto Hydramatic (Slim-Jim) that Olds had been using since 1961.
Along with the transmission and bodyshell, the engine was also new for 1965. It was a 425 cubic-inch Super Rocket V8 that was more powerful and of a more efficient design than the older 394 cubic-inch V8 previously used, yet it was much lighter in weight. The Ninety-Eight's standard and only engine offering for 1965 was the four-barrel "Ultra High Compression" version of the 425 Super Rocket rated at 360 horsepower (270 kW). It was the last Oldsmobile 98 generation with a manual transmission.
With a 127 inch (10.6 feet) wheelbase, length of 224.4 inches (18.7 feet), width of 80.0 inches (6.7 feet), a height of 54.8 inches (4.5 feet), and a weight of 4,168 lbs. (2.084 tons), the Ninety-Eight's continued to be the largest models produced by Oldsmobile.
New to the Ninety-Eight series were a recessed padded instrument panel, anti-theft lock within the steering column, rear view mirror map light, mini-buckle seat belts, and deeply padded head restraints. Standard for the Ninety-Eight's was the 365-HP 455 Rocket V-8 (7.5 liters) which required premium leaded gas; Turbo Hydra-Matic 400 transmission, power steering (vari-ratio), power brakes, power windows, power seat, custom sport seat, foam padded front seat, deluxe steering wheel, self-regulating electric clock, and wheel discs (hub caps).
Some of the available options were a tilt-telescope steering wheel, instant horn, four season air conditioning with comfortron, tinted glass windshield, 6 way power seat, divided front seat with dual controls, power trunk release (vacuum), power control (power windows & power locks), power front disc brakes, am-fm stereo radio, rear seat speaker, stereo tape player (8-track), power operated antenna, door edge guards, cruise control, left outside remote control mirror, cornering lamps, anti-spin rear axle, vinyl roof, flo-thru ventilation, and safety sentinel.
Of the Ninety-Eight series, the 1969's were the only models to have an attached hood extension. After receiving numerous complaints from dealership mechanics about hitting their heads on the extension, Oldsmobile changed the style of the hood in 1970, removing the extension, which resulted in a flat hood design. Between 1965 and 1975 Oldsmobile commissioned Cotner-Bevington to build professional cars, (ambulances and hearses), using the large Ninety-Eight chassis. Ironically, during the '60's (1968), the only Oldsmobile professionally made into a limousine was the smaller Toronado, known as the AQC Jetway 707. In 1970, the length grew to 225.2 inches.
Eighth generation (1971-1976)
Oldsmobile built its biggest full-size car in 1971 although wheelbase was unchanged from 1970. The 1971 through 1976 Ninety-Eight was very similar to the Oldsmobile 88 (which by now was called the "Delta 88") except the Ninety-Eight had rear Cadillac-esque tailfins to differentiate between the two full-size models. The standard 455 cubic-inch Rocket V8 was rated at 340 hp (254 kW) and designed to run on lower octane regular lead, low-lead or unleaded gasoline for the first time this year thanks to a General Motors-mandate that all engines be designed to run on such fuels in preparation for the catalytic converter equipped cars of 1975 and later years that absolutely required unleaded gasoline. Despite this, a few 1975 and 1976 Ninety Eights were released from this catalytic converter requirement in Canada and were given certification along with exemption from requiring unleaded gasoline. V8's were progressively detuned as production wore on in line with tighter emission standards. A new bodyshell was introduced this year that would last until the 1976 model year. They were the biggest and heaviest Oldsmobiles ever built, specifically the 1974 to 1976 models when federally mandated 5 mph (8.0 km/h) bumpers were added both front and rear that increased the overall length of the cars by several inches to 232.2 (5898 mm).
Trunk mounted louvers for the flow through ventilation system were only found on 1971 models (as in many other GM models of 1971). The louvers were moved to the door jambs for 1972-1976 models.
The 1974-76 Oldsmobile Ninety-Eight (as well as the 74-76 Olds Delta 88, Olds Toronado, Buick LeSabre and Buick Electra Park Avenue) were among the first US production cars to offer an air bag option beginning in 1974. Very few cars were so equipped. The high cost ($700) plus public uncertainty about the yet-to-be proven safety systems that are now universal in today's automobiles saw quite handily to that.
Ninety Eight Regency
For the 1972 model year, the Limited Edition Regency was offered to commemorate Oldsmobile's 75th anniversary. Each 1972 Oldsmobile Ninety-Eight Regency was registered at Tiffany's and included the specially styled interior with a black or covert "pillow effect" velour upholstery, and power split bench seat, in place of the power bench seat with rear clock. Tiffany touches include the Tiffany Gold paint (an exclusive custom metallic color created especially for this car), the clock has also been specially styled by Tiffany's and bears a white Oldsmobile emblem above the Tiffany's name on a golden face. Each 1972 Regency owner received a distinctive sterling silver key ring as a gift, if ever lost the keys could be dropped in a mail box, and Tiffany's would return them to the owner.
A total of 2650 75th anniversary Ninety-Eight Regencys were built, all of them 4 door hardtops. In 1973 the non-anniversary Regency stayed in the line up slotted just above the LS. The Regency package would remain available on the Ninety Eight throughout the 1996 model year when it would become a separate model nameplate.
Ninth generation (1977–1984)
The 1977 model was extensively redone and downsized, at the same time as the Oldsmobile 88. The new models, at around 4000 pounds curb weight, were over 800 pounds lighter, but headroom and rear seat legroom were increased compared to equivalent 1976 models. The 455 in³ engine was replaced by the smaller 403 in³ V8. The Olds 350 was now standard. A diesel version of the 350 was added in 1978. Beginning in 1979, production of the 98 was exclusive to Lansing as Linden Assembly was retooled to build the E-body cars.
Base LS models were available as sedans only, and the premium Regency model came as either a coupe or a sedan. 1981 saw the introduction of Buick's 252 in³ V6 as standard, as well as a new 4-speed THM200-4R automatic transmission. The new Regency Brougham model was introduced for 1982. This car featured plush "Prima" velour seats with embroidered emblems, cut pile carpeting, and electroluminescent opera lamps on the B-pillars. The LS model was discontinued. The 1983 models received a new grille, but were otherwise unchanged. The federal 5 mph (8.0 km/h) impact standard was rolled back for 1984, prompting GM to make major changes to the bumpers to save weight; predictably, this drastically reduced their effectiveness. An 8-track tape player was no longer an option.
Production ended in March 1984. These cars were actually sold concurrently with the new front-wheel drive 1985 model. The body style reference in GM Manufacturing became "D" for the carryover RWD models, and the new FWD cars became C-bodies (as was the former designation for the RWD cars).