The Mitsubishi Diamante was first revealed by Mitsubishi Motors at the 1989 Tokyo Motor Show and officially offered for sale in Japanese market in May 1990. The term ‘Diamante’ is used for ‘Diamond’ in three languages including Spanish, Portuguese and Italian. It was also regarded as the second generation model of Magna that replaced the wider Galant Sigma in 1983. Mitsubishi Verada was considered as the luxury Australian counterpart of the Mitsubishi Diamante.
There have been quite a number of rumors encircling the launch of diamante suggesting that the car was perhaps not intended to launch in the home market, or perhaps it was opted to release as a non-performance model. The major reason behind these rumors is the Japanese taxation regulations that were based on the vehicle’s width until 1989. The Diamante was manufactured with a width wider than 1700 mm (66.9 inch) which as much for it to qualify as luxury car. This means that it would have suffered heavy tax penalties compared to its rival models which fall just within the taxation regulations. However, the launch of Honda Legend in 1986 was the major factor that paved the way for launching Diamante. In order to compete with the popular Legend that led the basis for future Lexus and Infiniti lineup, Mitsubishi had no other option to launch their Diamante.
In 1989, the Japanese tax regulation had revised making the Diamante one of the hit car in the home market by 1990. During the bubble economy of the Japan, many of the customers preferred to have an executive car offered with most new offerings at that time.
First Generation (1990-1996)
The first generation Diamante offered as a 4-door hardtop lacking window sashes. Mitsubishi launched Sigma just five months after the introduction of Diamante. Sigma was offered with different features including taller roofline, 6-windows glasshouse, window sashes and front/rear alterations.
Three V6 engines were offered in Diamante, i.e. 2.0L, 2.5L and 3.0L of 6G7 family. Majority of the models came with 4-wheel drive option. Diamante was offered in United States as a replacement car for Sigma in 1992.
The front-wheel and all-wheel drive versions offered in Japanese market include: 20E, 25E, 25V, 25V-SE, 30V, 30R and 30R-SE being front-wheel drive versions, while 25V 4WD and 30R-SE 4WD were all-wheel drive versions.
Second Generation (1995-2005)
In January 1995, the second generation Diamante was launched by Mitsubishi. It was slightly larger than its previous model and headroom was enhanced further.
There were several engine options were available. The base model came with a 2.5-L MVV (lean burn) V6 engine which was later replaced by 2.5-L and 3.0-L engines. In later years, the Diamante received a high end 3.5-L MIVEC V6 engine developing 194 kW (264 PS; 260 hp) at 6000 rpm and torque of 324 Nm (239 lb-ft) at 4500 rpm.
The enhancement equipment was also introduced in later Diamante, including a distance/lane-keeping system used for tracking lanes and distance from the car moving ahead with radar and camera. This technology was introduced for the first time in 1992 Debonair. Other features were satellite navigation, 5-speed automatic transmission (for the first time in a transverse drivetrain) and the Tiptonic-style INVECS-II.