Powered initially by the "KE64" 1991 cc straight-six engine with twin carburettors and dual exhausts, the original A30 series developed at 5000 rpm, and had a maximum speed of . The front grille had an "MMC" badge, denoting the newly formed Mitsubishi Motors Corporation. From September 1970 the 6G34 Saturn 6 (1994 cc) engine was installed, and exclusive to the Debonair as the "Executive" trim package, increasing the engine's power output to which gave the car a top speed of . The badge on the front grille was changed to signify the Saturn engine was installed, and a "MCA-Jet" badge was also included. This model received the A31 model code. In October 1973 the Debonair underwent a facelift: the front turn signals were made smaller and moved upwards on the fenders, the front ventilation windows were deleted, and the L-shaped taillights were replaced by rectangular units. The model code was not changed.