GM J platform

J-body
A 1987 Vauxhall Cavalier II, the Vauxhall version of the GM J-body.
Overview
Manufacturer	General Motors
Production	1981–2005
Body and chassis
Class	Compact (North America) Mid-size (Global)
Layout	FF layout
Body style(s)	2-door convertible 2-door coupe 2-door notchback sedan 3-door hatchback 4-door sedan 5-door station wagon 5-door hatchback
Chronology
Predecessor	GM H platform (RWD) (North America)
Successor	GM2900 platform (Europe) GM Delta (North America)

The General Motors J platform, or J-body, is an automobile platform that was used by General Motors from 1981 to 2005. Marking the transition to front-wheel drive in the compact-car segment in North America, the J platform was the successor to the H platform, making it the third generation of compact cars designed by the company. Outside North America, the J platform was adopted by GM-controlled subsidiaries making the same transition to front-wheel drive, though as a mid-size car.

By 1990, General Motors began to change its usage of the J platform. To clear room for the 1990 Saturn S-Series, Buick and Oldsmobile ended their use of the J platform (and their presence in the compact segment). Outside of North America, the J platform was phased out in favor of the GM2900 platform (cars based upon the Opel Vectra). The best-selling variants of the J-platform (the Chevrolet Cavalier and its various Pontiac equivalents) would remain in production into the early 2000s, following several redesigns.

Replaced by the GM Delta platform, the J-platform vehicle would end production in June 2005; the final vehicle produced was a Pontiac Sunfire.

Background

The 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 Aska in Japan. Due to the exterior dimensions, and the engines offered being in compliance with Japanese regulations, the platform was classed in the favorable "compact" designation, and competed with other Japanese made products sold in the domestic market at the time. Isuzu also supplied kits for Holden's J-car version, the Camira.^[1]

It was decided that a common replacement would be developed to eliminate duplication of engineering effort and ensure parts interchangeability – a practice known as badge engineering or platform-sharing. 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.

In continental Europe, the car was sold as the Opel Ascona. In Britain, it was known as the Vauxhall Cavalier. Irrespective of badging, European production of the J-body occurred in plants in Germany, Belgium, and Britain.^[2] It was generally well received but was narrowly beaten to the European Car of the Year accolade by the Renault 9.^[3] At the time, it set new standards for performance and economy in this size of car in Europe; for instance, the 1.6 petrol engined Cavalier for the British market had a top speed of 105 mph, compared to the 101 mph top speed of the 2.0 petrol engined Ford Cortina – its key competitor.^[2]

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

Models

Over its 24-year production run, the GM J platform would be sold under 16 different nameplates (five under the Pontiac brand alone). In North America, during the 1980s, every division of General Motors except for GMC sold a variant of the J platform.

Aside from several cosmetic redesigns (in 1988 and 1995) along with major powertrain revisions, the J-platform saw few fundamental changes during its production run.

Vehicle Name	Years Produced	Body Styles	Notes
North American-produced nameplates
Buick Skyhawk	1982–1989	2-door sedan 4-door sedan 3-door hatchback 5-door station wagon	The 1989 Buick Skyhawk would be the last Buick sold with a manual transmission until 2011.
Cadillac Cimarron	1982–1988	4-door sedan	The Cadillac Cimarron shared most of its body panels with the Chevrolet Cavalier, becoming one of the most infamous examples of automotive badge engineering.
Chevrolet Cavalier	1982–2005	2-door sedan 2-door coupe 2-door convertible 4-door sedan 3-door hatchback 5-door station wagon	Longest-produced and best-selling J-body.
Oldsmobile Firenza	1982–1988	2-door sedan 4-door sedan 3-door hatchback 5-door station wagon	The Oldsmobile Firenza is the shortest-produced version of the J-platform in North America.
Pontiac J2000 Pontiac 2000 Pontiac 2000 Sunbird Pontiac Sunbird	1982 (J2000) 1983 (2000) 1984 (2000 Sunbird) 1985–1994 (Sunbird)	2-door sedan 2-door coupe 2-door convertible 4-door sedan 3-door hatchback 5-door station wagon
Pontiac Sunfire	1995–2005	2-door coupe 2-door convertible 4-door sedan	The Sunfire replaced the Sunbird as part of a major redesign of the J-platform for 1995.
Worldwide-produced nameplates
Chevrolet Monza	1982–1996	2-door sedan 4-door sedan 3-door hatchback	Produced in Brazil, the Monza is a version of the Opel Ascona. 3-door hatchbacks have different (more upright) rooflines than the North American versions.
Daewoo Espero/Aranos	1990–1997	4-door sedan	Only version of the J-platform using a body styled by Bertone
Holden Camira	1982–1989	4-door sedan 5-door station wagon	The body of the Camira station wagon served as the basis for the Vauxhall Cavalier wagon in the UK.
Isuzu Aska	1983–1989	4-door sedan	The Aska was sold as a Chevrolet in South America, and briefly as the Holden JJ Camira in New Zealand.
Opel Ascona C Vauxhall Cavalier Mark II	1982–1988	Opel: 2-door sedan 4-door sedan 5-door hatchback Vauxhall: 2-door sedan 2-door convertible 4-door sedan 5-door hatchback 5-door station wagon	The Ascona/Cavalier are badge-engineered vehicles, with the Opel sold in continental Europe and the Vauxhall sold in Great Britain. Station wagon body panels are derived from the Holden Camira produced in Australia.
Toyota Cavalier	1995–2000	2-door coupe 4-door sedan	In a trade agreement between Toyota and GM, the Cavalier was imported into Japan in return for the USDM Geo-division cars for Chevrolet. Toyota Cavaliers are right-hand drive with other detail changes to meet Japanese regulations.

In all cases, final assembly of convertibles was subcontracted by General Motors; in North America by American Sunroof Corporation (ASC); in Brazil by Envemo and Sulam – and in Europe by Baur. Convertibles for the German market were assembled by Keinath and Hammond & Thiede.

Approximately 10,150,000 GM J platform cars were sold across eleven marques on six continents from 1982 through 1997, not counting Daewoo Espero sales.^[4][5][6][7] Consequently, it is the fifth best selling automobile platform in automotive history.

References

1. "GM ties with two Japanese car makers". Nihon Keizai Shimbun. Tokyo: 1. August 18, 1981.
2. Hayward, Matthew (June 28, 2011). "Vauxhall Cavalier Mk2: Vauxhall's new pragmatism...". AROnline. Retrieved 2013-09-04.
3. "Previous winners". Car of the year. Retrieved 2010-09-18.
4. Flammang, James Standard Catalog of American Cars 1976–1999 3rd Edition (Iola, WI: Krause Publications, Inc 1999)
5. "International 1st Gen Jbodies – First Generation Forum". j-body.org. Retrieved 2012-02-16.
6. "Overview". Ascona. Archived from the original on March 30, 2012.
7. "Chevrolet Monza". Chevy Wiki. February 9, 2009. Retrieved 2012-02-16.

• List of GM VIN codes