The Mitsubishi Debonair is a four-door luxury car, introduced by Mitsubishi Motors in 1964 to serve as their flagship passenger vehicle in the Japanese domestic market. Three distinct generations were available during its 35-year production run until it was discontinued in 1999.

First generation

Powered by the KE64 1991cc straight-6 engine with twin carburettors and dual exhausts, it developed 105PS (104hp/77kW) at 5,000rpm, and had a maximum speed of 155kilometres per hour (96mph). During the 1970s, the Saturn 6 1994cc straight-6 engine was adopted, boosting power to 132PS (130hp/97kW) and giving the car a top speed of 180kilometres per hour (112mph). Although it received several minor redesigns (denoted I through IV in Roman numerals), the vehicle proved popular enough in the executive market to remain in production for 22 years without major modifications.

Second generation

In 1986 the Debonair adopted a front-wheel drive format, in order to accommodate an increase in interior space. It also came with Mitsubishi's first V6 engines, the 6G71 2.0L and the 6G72 3.0L. A supercharged version of the smaller engine was added to the line-up in 1987, using the world's first needle roller rocker arm assembly. This generation, and its successor, were also sold as the Hyundai Grandeur.

Third generation

The third model debuted in 1992, longer and wider than its predecessors. The wider range of available engines was now topped by a 260PS (256hp/191kW) 6G74 3.5L DOHC V6, and as Mitsubishi's domestic flagship incorporated much of the company's technology, including four-wheel steering, four-wheel anti-lock braking system, electronically controlled suspension, and INVECS automatic transmission with traction control.

It was discontinued in 1999, and directly replaced by the Proudia. However, Mitsubishi also developed its first V8 engine for the new Dignity luxury car around this time, and it was this latter model which took position as the domestic flagship of the company.