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
Luxury vehicle engineering is often used for cost savings, for example, the Lincoln vehicles that are based on Ford platforms or Acura models derived from Honda. Though widely used, the term luxury is broad and highly variable. It is a perceptual, conditional and subjective attribute and may be understood differently by different people: "What is a luxury car to some... may be 'ordinary' to others." According to the European Commission, the "luxury vehicle" segment is classified as F-segment. However, the boundaries between the traditional segments are increasingly becoming blurred and diluted as features once exclusive to luxury vehicles become standard equipment on