GM C platform, also known as the C-Body, was a
front wheel drive
Front-wheel drive (FWD) is a form of internal combustion engine, engine and transmission (mechanics), transmission layout used in motor vehicles, in which the engine drives the front wheels only. Most modern front-wheel-drive vehicles feature ...
(FWD) automobile platform used by
General Motors
General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. The company is most known for owning and manufacturing f ...
' Cadillac, Buick and Oldsmobile divisions for their full-sized automobiles from 1985 through 1996, sharing unibody construction, transverse engine configuration, rack and pinion steering and four-wheel independent suspension.
C-Bodies used, V6 or V8 engines, GM's TMH440 transaxle (initially), unibody construction — and all had been aerodynamically improved, with the Oldsmobile achieving a .383 drag coefficient.
GM's C platform and
H platform were largely identical, sharing the same 110.8 in wheelbase, most bodywork, interior details, glass and engines. Manufacture began with the C platform in late 1983, first at two purpose-built plants,
Wentzville Assembly and
Orion Assembly
Orion Assembly is an automotive assembly plant in Orion Township, Michigan, United States, owned and operated by General Motors. From late 2025, the plant is slated to assemble the Chevrolet Silverado EV and GMC Sierra EV battery electric p ...
— later moving to
Lansing Car Assembly
Lansing Car Assembly was a General Motors automobile factory in Lansing, Michigan. It contained two elements, a 1901 automobile plant in downtown Lansing, and the 1920 Durant Motors factory on Lansing's Far Westside.
The Lansing plant was the h ...
as well as Flint and Willow Run assembly plants.
Significantly shorter, narrower, lighter and more fuel-efficient than the platform they replaced, the C Platform vehicles were noted for having nearly the same key interior dimensions as their predecessors and a much more nearly flat passenger compartment floor
— albeit with thinner seats and dramatically less upper
tumblehome
Tumblehome or tumble home is the narrowing of a Hull (watercraft), hull above the waterline, giving less beam (nautical), beam at the level of the main deck. The opposite of tumblehome is flare (ship), flare.
A small amount of tumblehome is nor ...
, locating windshield as well as side glass closer to passengers.
Introduced in early 1984, the models were marketed as the
Oldsmobile Ninety-Eight
The Oldsmobile 98 (spelled Ninety-Eight from 1952 to 1991, and Ninety Eight from 1992 to 1996) is the full-size flagship model of Oldsmobile that was produced from 1940 until 1942, and then from 1946 to 1996. The name – reflecting a "Series ...
(11th gen),
Buick Electra
The Buick Electra is a full-size luxury car manufactured and marketed by Buick from 1959 to 1990, over six generations. Introduced as the replacement for the Roadmaster lines, the Electra served as the flagship Buick sedan line through its en ...
(6th gen) and
Cadillac Deville
The Cadillac DeVille is a model name used by Cadillac over eight generations, originally to designate a trim level of the 1949 Cadillac Series 62 and later for a standalone model in the brand range. The last model marketed specifically as a ''D ...
(6th gen) and
Fleetwood
Fleetwood is a coastal town in the Borough of Wyre in Lancashire, England, at the northwest corner of the Fylde. It had a population of 25,939 at the 2011 United Kingdom census, 2011 census.
Fleetwood acquired its modern character in the 1830 ...
(1985–90)..
Cadillac would later introduce C Body models with a 113.8 in wheelbase. Most C-body vehicles were ultimately replaced with cars on the related
G,
H, and
K platform designations.
The
Cadillac Series 75 limousine briefly made its return on this platform, stretched by 23.6" to a wheelbase of 134.4". Cadillac used the platform though 1993; Buick heavily revised the Electra, becoming the first generation
Buick Park Avenue
The Buick Park Avenue is a full-size car built by Buick. The nameplate was first used in 1975 for an appearance option package on the Electra 225 Limited. It became an Electra trim level in 1978 and its own model starting in the 1991 model year ...
(1991–1996), while still using the C Platform; and Oldsmobile marketed C Platform derivatives through 1990, notably the
Oldsmobile Touring Sedan
The Oldsmobile 98 (spelled Ninety-Eight from 1952 to 1991, and Ninety Eight from 1992 to 1996) is the full-size car, full-size flagship model of Oldsmobile that was produced from 1940 until 1942, and then from 1946 to 1996. The name – refle ...
.
Models using the C Platform
Related H body models
The
H platform and C platform were largely identical, sharing the same 110.8 in wheelbase, most bodywork, interior details, glass and engines.
References
List of GM VIN codes{{General Motors platforms
C