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
Toyota S engine customers in 1999. Toyota S engine The Toyota S Series engines are a family of straight-4 engines with displacement from 1.8 L to 2.2 L produced by Toyota Motor Corporation from January 1980 to August 2007. The series has cast iron engine blocks and alloy cylinder heads. The 1S is the first version of the S-series engine. It is a member of Toyota's "Lasre" engine family ("Lightweight Advanced Super Response Engine"). Bore and stroke are 80.5 x 90.0 mm. The engine was first seen in 1981, and was fitted to a wide range of Toyotas, in both RWD and FWD