Toyota Mark X late 1960s. Instead of being based on a modified Supra chassis "A" series platform, the Mark X continues to use the Toyota "X" platform, and does not share its platform with the Toyota "S" series platform used under the Toyota Crown and the Lexus GS. The continuation of describing this vehicle as the "X" series is a reference to the first dedicated Mark II platform introduced in 1972. Major changes to the Mark series are the engine and footwork. Toyota discontinued the straight-six engines used in the Toyota Verossa, which included the JZ series and the G series engines, and
Personal luxury car . This marketing approach was also used in Japan, where the early 1970s saw the introduction of the Toyota Crown coupe, followed by the coupe versions of the Nissan Cedric and Nissan Gloria, and the Mazda Luce. In the 1980s the Toyota Soarer, Nissan Leopard, Mazda Cosmo, and the Honda Legend were popular with Japanese buyers. Throughout the 1970s American "personal luxury" cars grew ever larger, heavier, and more luxurious. By the early 1980s, however, they were typically equipped with either a V6 or a dramatically detuned V8 engine in order to comply with increasingly strict vehicle emissions standards. In