The Mercedes-Benz S350d was a diesel powered variant of the W222 S-Class Sedan that was introduced for the 2014 model year. Initially sold as the W221 S350 BLUETEC 4MATIC, the S350d was first equipped with Mercedes' OM 642 LS DE 30 LA engine, which was a 255hp turbocharged V6 with 457 lb ft of torque. This engine was replaced for the 2018 model year by the OM 656 DE29T LA powerplant, which was a turbocharged inline six with 288hp and 443 lb ft of torque. From launch until early 2015, a 7 speed automatic transmission was used. After, a 9 speed automatic was standard, with both gearboxes sending drive to the rear wheels. Production of the W222 Mercedes-Benz S350d lasted until 2020, when the next generation W223 Mercedes-Benz S-Class debuted.