GM J platform

The J platform, or J-body, was General Motors' inexpensive front-wheel drive automobile platform from the 1980s and 1990s. The platform replaced the GM H platform. The first J-body cars were the Chevrolet Cavalier, Pontiac J2000, and the Oldsmobile Firenza which entered production on March 23, 1981 as 1982 models. The Cavalier was phased out at the end of 2004 in favor of the new Chevrolet Cobalt. The last surviving J-body car, the Mexican-built Pontiac Sunfire, ended production in June 2005. There are three generations of the J-body: 1982 to 1987 (or until 1988 or 1989 depending on the model), 1988 to 1994, and 1995 to 2005.

Except for cosmetic differences, engine upgrades and the discontinuation of certain models, the platform remained largely unchanged throughout the years.

Design of the J-body dated back to the mid-1970s. At that time, GM-controlled divisions in different parts of the world manufactured totally different rear-wheel drive C-segment cars - the Chevrolet Vega in America, the Vauxhall Cavalier/Opel Ascona in Europe, the Holden Torana in Australia and the Isuzu Florian in Japan. Some of them were not particularly competitive, so it was decided that a common replacement would be developed to eliminate duplication of engineering effort and ensure parts interchangeability. When the Arab Oil Embargo forced CAFE mandates, and the fear of US$3.00 for a gallon of gasoline, the J-body was practically produced straight off the drawing board.

The fourth character in the Vehicle Identification Number for a J-body car is "J".

Many vehicles used this platform including the following American nameplates:
 * 1982–1988 Cadillac Cimarron
 * 1982–1988 Oldsmobile Firenza
 * 1982–1989 Buick Skyhawk
 * 1982–2005 Chevrolet Cavalier
 * 1982 Pontiac J2000
 * 1983 Pontiac 2000
 * 1984 Pontiac 2000 Sunbird
 * 1985–1994 Pontiac Sunbird
 * 1995–2005 Pontiac Sunfire

International J-bodies include:
 * 1982–1988 Opel Ascona C (Europe and South Africa)
 * 1982–1988 Vauxhall Cavalier Mk II (United Kingdom)
 * 1983–1989 Isuzu Aska (Japan) (originally called Florian Aska)
 * 1982–1989 Holden Camira (Australia and New Zealand)
 * 1982–1996 Chevrolet Monza (Brazil)
 * 1995–2000 Toyota Cavalier (Japan)
 * 1990–1997 Daewoo Espero (South Korea)

Bodystyles included;
 * 2-door sedan - North America (until 1987), Brazil, Europe
 * 2-door coupé - North America (from 1988)
 * 4-door sedan - all markets
 * 3-door hatchback - North America (until 1987)
 * 3-door hatchback - Brazil (NOTE: these are two different bodies, the Brazilian version had a more upright roofline than the USDM one)
 * 5-door hatchback - Europe
 * 5-door station wagon - North America (until 1994), Australia (exported to the UK)
 * 2-door convertible - subcontracted to American Sunroof Corporation in North America and Baur in Europe; German market convertibles made by two different coachbuilders: Keinath and Hammond & Thiede. Brazilian convertibles made by Envemo and Sulam