The Mitsubishi Diamante is an automobile that was manufactured by Mitsubishi Motors from 1990 to 2005. The first series was a hardtop introduced to the public at the Tokyo Motor Show in 1989. It went on sale in Japan exclusively in May 1990 and won that year's Japan Car of the Year award. It was created by splicing an extra right down the middle of the Mitsubishi Galant, which itself had won the Japan Car of the Year award in 1987. The Diamante's platform was also used for the sporty Mitsubishi 3000GT.
The name Diamante was derived from the Spanish, Portuguese, and Italian word for "diamond" and was adopted also as homage to the Mitsubishi badge which is composed of three diamonds. In Japan, this vehicle was sold at the retail chain Car Plaza.
History From 1991, a more conventional Diamante-derived Mitsubishi Sigma sedan was also built in Japan for its domestic and European export markets. It became the basis of the second generation Magna independently built in Australia. Its Australian luxury derivate, sold as the Verada, became the Diamante for export markets including New Zealand and North America a year later. The Wagon version was also exported including to Japan.
There have been rumors that the Diamante was either not intended for a Japanese launch, or it might have been planned as a low-volume model. The reason for this argument is that until 1989, the width of vehicles impacted the taxation class. The Diamante, being wider than the breakpoint, would have suffered a large tax penalty against most of its rivals, which were designed to be just inside that vital limit. At the time, Mitsubishi's international image was also considered less than ideal for the marketing of a luxury car — its most expensive offering at the time, the Debonair, was largely seen as a company car project for Mitsubishi conglomerate executives. The Diamante's introduction was the result of the Honda/Acura Legend, which caught manufacturers by surprise when it appeared in 1986, inspiring the creation of the Lexus and Infiniti divisions, as well as various executive car class vehicles to be revised as a result. Mitsubishi needed to compete with the Legend and the Diamante was the result.
However, the tax situation changed in 1989, and the Diamante became the surprise hit of 1990. Amidst Japan's bubble economy, many private car owners sought an executive car in a market that had very few new offerings that year.
First generation (1990–1995)
The first generation Diamante was produced in three versions: Four-side window hardtop: a four-door hardtop with frameless windows that was solely built in Nagoya, Japan, and only sold in Japan and North America. It featured advanced electronic aids such as four-wheel steering (4WS). Six-side window sedan: a more conventional variant built and introduced in Japan five months after the Diamante. It was called the Sigma and differed by having a slightly taller roofline, a six-window glasshouse, window sashes, revised front fascia and rear styling. It was exported to Europe from Japan and formed the basis of the second generation Magna/Verada sedan, which was independently built in Adelaide, South Australia. Its luxury derivative, the Verada was intended for the domestic consumption and primary export to North America (but export to North America never happened) (hence the longer bumper bars to meet the latter's more onerous crash standards). Wagon: this was the wagon version of the above-mentioned sedan, designed and manufactured exclusively by Mitsubishi Australia. It was introduced in late 1992 for the 1993 model year.
Japan The Japanese Diamante hardtop was built from 1990 until 1995 and was available in front wheel drive (FWD) and all-wheel drive (AWD). Some models featured four-wheel steering (4WS).
FWD versions featured an independent suspension design with MacPherson struts at the front and multi-link in the rear. This version was available with a range of engines listed below, some with five-speed manual in addition to four-speed automatic transmission. AWD Diamantes come in three models: the 25V 4WD, 30R 4WD and the flagship 30R-SE 4WD. All have MacPherson strut front suspension with double wishbones at the rear. Both front and rear brake discs are ventilated. The AWD Diamante sits lower than a standard FWD Diamante and has a 70-liter fuel tank instead of the FWD's 72-liter tank.
This range of vehicles was powered by three V6 engines (of 2.0-, 2.5- and 3.0-liter capacity) of the 6G7 family; AWD was available on most models. Perhaps contrary to its overseas image, Mitsubishi at the time fully emphasized the use of electronic gadgets in its cars and the Diamante is notable for a long list of such features. Each engine choice obligated buyers in Japan to pay more annual road tax and the level of standard and luxury equipment increased accordingly.
Chief among these was: The world's first autonomous cruise control system labelled Preview Distance Control; An electronically controlled active trace and traction control system that Mitsubishi developed and was the first integration of these two systems in the world. Simply labelled "TCL" in 1990, the system evolved into Mitsubishi's Active Skid and Traction Control (ASTC) system. Developed to help the driver maintain the intended line through a corner, an onboard computer monitored several vehicle operating parameters through various sensors. In essence, when too much throttle was applied while negotiating a curve, engine output and braking would be automatically regulated to ensure the proper line through the curve is followed and to provide the proper amount of traction under various road surface conditions. While conventional traction control systems at the time featured only a slip control function, Mitsubishi's newly developed TCL system had a preventive (active) safety function which improved the course tracing performance by automatically adjusting the traction force (called "trace control") thereby restraining the development of excessive lateral acceleration while turning. Although not a proper modern stability control system, trace control was able to monitor steering angle, throttle position and individual wheel speeds but without any yaw input. In addition, this TCL system also works together with Diamante's electronic controlled suspension and four-wheel steering that Mitsubishi developed to improve total handling and performance.
The Diamante won the Car of the Year Japan award in 1990–1991 and its model range was as follows:
20E The 20E is the base model Diamante. It comes with a 2.0-liter 6G71 SOHC 12-valve V6 engine outputting at 5500 rpm and at 3500 rpm. It is available as both a five-speed manual and four-speed automatic, with 14-inch steel wheels. Standard equipment includes power windows, speed sensitive power steering, power mirrors, climate control and a four-speaker AM/FM radio with cassette. Optional extras were a rear wiper and alloy wheels. It has the F11A frame number. In October 1992 this engine was replaced by the new 24-valve 6A12 engine, with the same overall displacement but a shorter stroke. Power increased to and the chassis number became F12A.
25E
The 25E has the same features as the 20E but replaces the 20E's 2.0-liter engine with a 2.5-liter unit. The 25E's 2.5-liter 6G73 V6 engine outputs at 6000 rpm and at 4500 rpm. The 25E has a frame number of E-F13A.
25V The next model in the model range is the 25V. The 25V is almost the same as the 25E, although is identified with a different frame number reflecting the fact that four-wheel steering was equipped (E-F15A). It uses the same 2.5-liter 6G73 V6 engine, outputting at 6000 rpm and at 4500 rpm. It is available in four-speed automatic transmission and 15-inch alloy wheels. In addition to the 20E equipment, the 25V also features speed sensitive power steering, leather-wrapped steering wheel and ventilated rear brake discs for maximum braking performance. Optional was a rear wiper.
25V-SE The 25V-SE is the top of the range 2.5-liter Diamante variant. As with its lower variants the 2.5-liter 6G73 V6 engine is used. Like the 25V upon which it is based, it is only available as an automatic. In addition to the 25V equipment, the 25V-SE features anti-lock braking system (ABS), traction control system (TCS) and electric-powered seats. Optionals are the rear wiper and leather interior. It is identified by the same E-F15A frame number as the 25V. There was also a version of this without the four-wheel steering called the 25V-S, with chassis code F13A.
30V The 30V is the base 3.0-liter FWD Diamante base. It comes with a 3.0-liter 6G72 V6 outputting at 6000 rpm and at 3000 rpm. It is only available in automatic. The FWD Diamante Wagon comes with a 3.0-liter 6G72 V6 outputting at 5000 rpm and at 4000 rpm. On top of the 25V equipment, the 30V features cruise control, remote central locking, six-speaker AM/FM cassette player and TCS. Leather interior and rear wiper remain optional. The frame number of the 30V is E-F17A, F07W for the wagon (although it is sometimes referred to as "K45" as well).
30R The 30R is the middle of the 3.0-liter FWD Diamante range. It uses the 3.0-liter 6G72 V6 outputting a 6000 rpm and at 3000 rpm. As with all higher spec Diamantes it is available in automatic only. The 30R, which sold for more than the 30V has everything of the 30V except for TCS and ABS. The only addition is a front spoiler. The 30R is identified with the same E-F17A frame number.
30R-SE The 30R-SE is the top of the FWD Diamante range. It uses the same 3.0-liter V6 as the 30R/30V and again is automatic only. The 30R-SE has all the equipment fitted to the 30V but active suspension granting it a road height. Externally, it also features the front spoiler of the 30R. Its frame number is E-F17A.
25V 4WD The 25V 4WD is the entry level Diamante with AWD. It has a frame number of E-F25A.
The 25V comes with a 2.5-liter 6G73 V6 engine, outputting at 6000 rpm and at 4500 rpm. Standard equipment includes speed sensing power steering, power windows, power mirrors, cruise control, leather steering wheel, alloy wheels, remote central locking, climate control and a four speaker AM/FM radio with cassette player. Optional is full leather interior and a rear wiper.
30R-SE 4WD The 30R-SE 4WD is the flagship of the Diamante range. It has the frame number of E-F27A as it is the same basic vehicle as the 30R. The only difference between the 30R-SE and 30R is the addition of a CD player.
North America
The Diamante sedan was first sold in the US in spring 1991 for the 1992 model year, replacing the Sigma. Mitsubishi Motors North America sourced their Diamante hardtop sedans from Japan and the wagons, introduced in late 1992 for the 1993 model year from Australia. The Diamante was originally available in two trim levels, the base and LS, and only as FWD automatics. The base model used the 6G72 3.0-liter V6 rated at , and shared with the Diamante wagon. The LS sedan got a dual-cam version of the 6G72, rated at . Standard equipment for ES included central locking, driver's airbag, power windows and power mirrors. Optional was ABS, cruise control, alloys and sunroof. The LS added alloy wheels, cruise control and ABS to the standard equipment list. A manual sunroof and leather were optional.