Merecedes-Benz introduced their second generation of the M-Class, the W164, for the 2006 model year. The W164 featured numerous updates to the chassis and interior, as well as drivetrain. The second generation M-Class was offered with a V6 or V8 engine, no longer featuring the inline four engine available in the first generation W163. Variants built included the ML320 CDI 4MATIC, ML350 4MATIC, ML350 CDI BlueTEC 4MATIC, ML500 4MATIC, ML550 4MATIC, and ML63 AMG 4MATIC. Although all variants were equipped with Mercedes' 4MATIC all wheel drive system, 4MATIC branding was only used on all variants after 2006. Production of the W164 Mercedes-Benz M-Class ended in 2011, when it was replaced by the next generation W166 Mercedes-Benz M-Class.