The Mercedes-Benz GLS550 4MATIC was a variant of the X166 GL-Class that debuted for the 2016 model year after a facelift and renaming of all GL-Class variants to GLS-Class. The GLS 550 4MATIC was powered by Mercedes' M278 DE46 engine, which was a 449hp twin-turbo 4.7L V8 paired to a 7-speed 7G-Tronic automatic transmission that sent power to all four wheels. The X166 Mercedes-Benz GLS 550 4MATIC ended production in 2019, when Mercedes introduced the next generation X167 GLS-Class.