Subaru introduced the Impreza for the 1993 model year. The first generation Impreza was offered as a series of compact coupes, sedans, or five door hatchbacks, all powered by a flat four engine. Subaru has always been very loyal to the 'boxer' engine, and the Impreza has always featured a range of naturally aspirated or turbocharged units. The Impreza was used as the basis for the Outback Sport model, and included a range of trim levels such as LX, GL, and Sport. In order to showcase the Impreza's all wheel drive capabilities, Subaru participated in a wide range of off road motorsports, including the World Rally Championship, in which they won numerous titles. These exploits gave birth to the regarded WRX and WRX STi performance variants. A wide range of special editions were also built during the first generation, such as the Series McRae, RB5, P1, and legendary 22B STi. The U.S. did not recieve the WRX or WRX STi for the first generation of production, but Subaru marketed the 2.5RS as the American performance variant. The first generation Impreza ended production in 2000, and was replaced by the Second Generation Subaru Impreza.