Mitsubishi Diamante 3.5L V6
The Mitsubishi Diamante, sold as the Sigma in Japan, was Mitsubishi's ambitious bid for the executive sedan market. Launched in 1990, the first generation won Japan's Car of the Year award and featured advanced technology including four-wheel steering and electronically controlled suspension.
The second generation, arriving in 1995, brought a more refined design and the potent 3.5-liter 6G74 V6 engine with MIVEC variable valve timing producing 245 horsepower. The INVECS-II adaptive automatic transmission learned the driver's habits and adjusted shift patterns accordingly, a sophisticated feature for its era.
In its home market, the Diamante was positioned as a prestigious executive car, competing with the Toyota Crown and Nissan Cedric. In North America, it was marketed as a value alternative to the Lexus ES and Acura TL, offering similar levels of comfort and equipment at a lower price point.
Despite its technical merit, the Diamante never achieved the sales success Mitsubishi hoped for in export markets. The brand lacked the cachet of Toyota's Lexus or Honda's Acura in the luxury space. Production ended in 2005 as Mitsubishi refocused its lineup. Today, the Diamante is an overlooked and undervalued executive sedan that offers considerable luxury for minimal investment.
Very affordable to buy but parts are increasingly scarce. The 3.5L 6G74 is reliable but check for timing belt service history. INVECS-II transmission generally holds up well but fluid changes are critical. Rust is the biggest enemy on surviving examples. Interior plastics can become brittle. AWD models have additional maintenance requirements. Most remaining examples are second-generation US-spec cars.
First generation (1990-1996) won Japan Car of the Year. Second generation (1996-2005) offered in both FWD and AWD configurations. Sold as Sigma in Japan for the first generation, then as Diamante globally. Discontinued in 2005 as Mitsubishi restructured.