In February 1972 Mitsubishi upgraded the power plants, replacing the lower powered versions with a somewhat larger (1.7 litre) version of the Saturn engine. These cars received the A55C chassis code, while the twin-cam MR continued to use the smaller but more powerful 4G32 engine until January 1973, when stricter emissions standards made it obsolete. The higher-end versions then received Mitsubishi's all new Astron engine, with either , along with a new A57C chassis code. The range now consisted of the "SL" (2000 cc single-carb, four- or five-speed manual or automatic transmission), "GS-5" (2000 cc twin-carb, 5-speed manual) and "GSR" (2000 cc twin-carb, five-speed manual). The lowest priced 1700 SL model remained with the 1.7, with . The lineup was also given a mild facelift to signal the changes, comprising a one-piece slats-type grille with a central dividing molding and three-piece tail lights. Additionally, the more sporting GSR had wider 185-section tires, flared guards and a black-painted rear panel between the lights.