The fourth generation of Dodge Viper was introduced for the 2008 model year. The fourth generation, known as the ZB II, was known as the Viper SRT-10, and was offered in Roadster and Coupe body styles. Importantly, the styling for this generation did not receive any substantial changes to its exterior, but featured an updated interior, and a wide range of mechanical upgrades. The ZB II was powered by an 8.4L V10 engine that produced 600hp and sent power to the rear wheels through a manual six speed transmission. A variety of special editions were created, including the notable American Club Racer (ACR), and track only ACR-X. Production of the ZB II Viper lasted until 2010, when the Fifth Generation Dodge Viper (VX I) debuted.