The Mercedes-Benz S 450 4MATIC was a variant of the W221 S-Class that was introduced for the 2007 model year. The S450 4MATIC was also available in rear wheel drive layout, and was powered by Mercedes' M273 E45 engine. The M273 E45 was a 4.5L naturally aspirated V8 engine that generated 335hp. The W221 S450 4MATIC was built until 2013, although the model series would continue in the next generation W222 Mercedes-Benz S-Class as the W222 S450 4MATIC