The General MotorsJ 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 reduce its usage of the J platform, reducing its usage of badge engineering. As the company prepared the launch of the Saturn S-Series for 1990, Buick and Oldsmobile ended their use of the J platform. Outside of North America, the J platform was phased out in favor of the GM2900 platform. With its highest sales under the Chevrolet and Pontiac brands, the J platform remained in production into the 2000s, following several redesigns. Replaced by the GM Delta platform, General Motors ended production of the J-platform in June 2005, with a Pontiac Sunfire as the final example.
Background
The design of the J-body began in 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 Vegain America, the Vauxhall Cavalier/Opel Ascona in Europe, the Holden Torana in Australia and the Isuzu Florian in Japan. 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 Corporate average fuel economy 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. It was generally well received but was narrowly beaten to the European Car of the Year accolade by the Renault 9. The Vauxhall Cavalier version was particularly successful in Britain, where it was the second best selling car in 1984 and 1985 and managed around 800,000 sales across a seven-year production run. 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 for a year until the Ford Sierra was launched in 1982. Due to the exterior dimensions, and the engines offered being in compliance with Japanese regulations, the platform was classed in the favorable "compact" designation allowing the Isuzu Aska to compete 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. 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. In North America, during the 1980s, every division of General Motors except forGMC sold a variant of the J platform. Aside from several cosmetic redesigns along with major powertrain revisions, the J-platform saw few fundamental changes during its production run. In all cases, final assembly of convertibles was subcontracted by General Motors; in North America by American Sunroof Corporation ; in Brazil by Envemo and Sulam – and in Europe by Baur. Convertibles for the German market were assembled by Keinath and. Across all US brands, introduction was in spring 1981 but the launch versions were all advertised as 1982 model year cars. 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. Consequently, it is the fifth best selling automobile platform in automotive history.
