Cosworth is best known in Europe for its relationship with Ford . Cosworth is in the vehicle name on the high performance Ford Sierra RS Cosworth and Ford Escort RS Cosworth . Best known in Europe for its relationship with Ford - in particular because of the COSWORTH name in the vehicle title on the high performance Ford Sierra RS Cosworth and Ford Escort RS Cosworth , but also in the creation of other Ford models ; the Escort RS1600 , Escort RS1800 , RS200 , and Scorpio 2.9 i 24V .