See main article: Chrysler Sigma, Mitsubishi Diamante and Mitsubishi Galant.
Mitsubishi Sigma is a model name that was used by the Japanese automobile manufacturer Mitsubishi Motors between 1976 and 1996. Mitsubishi has utilized the "Sigma" name on several different vehicles based on Mitsubishi Galant and Mitsubishi Diamante sold in various markets during this time. The GSX-R 2.0 turbo model was fitted with a Single Overhead Cam cyclone motor which was the precursor to the infamous 4G63T twin cam motor. The 1987 model had a wheelbase that would be ideally suited to FWD street drifting. Passengers would often question life choices and later refer it as 'the suicide sigma'
Between 1976 and 1987 over three generations, the Mitsubishi Galant sedan sold in Japan was suffixed with the "Σ" (sigma) badge.
Between 1980 and 1987 over two generations, the version of the Mitsubishi Galant sedan and station wagon produced and sold in Australia retailed under the Mitsubishi Sigma name. Between 1977 and 1980, prior to Mitsubishi taking over Chrysler Australia's operations, this model had been referred to as Chrysler Sigma.
Between c. 1977 and c. 1988 over three generations, the version of the Mitsubishi Galant sedan and station wagon sold in New Zealand retailed under the Mitsubishi Sigma name.
The sedan bodywork of the Mitsubishi Galant (fifth generation) was sold in North America from 1987 for the 1988 model year as the Mitsubishi Galant Σ (sigma), and from 1988 to 1990 for the 1989 and 1990 model years as the Mitsubishi Sigma.
A six-window, pillared sedan version of the first generation of the Mitsubishi Diamante hardtop sedan was sold in Japan and Europe as the Mitsubishi Sigma between 1991 and 1996. In Europe, the Australian-built station wagon derivative was also sold under the Sigma name. The Sigma also formed the basis of the Australian-made Mitsubishi Magna (second generation).