Externally, the new G-Class bears a striking resemblance to its predecessor. However, Mercedes has made changes under the hood, with the most significant being the replacement of the V8 engine in the G550 with an inline six-cylinder engine. In Europe, the diesel engine remains, and its power has even been increased. This comes as a pleasant surprise considering the stringent emissions regulations in the EU.

Although images are not yet available, the outgoing G400d is retiring to make way for the G450d. It utilizes a version of the 3.0-liter inline six-cylinder turbodiesel tuned to produce 362 horsepower and 553 pound-feet of torque. This gives it an advantage of 36 horsepower and 37 pound-feet of torque compared to its predecessor. Additionally, the new diesel features a mild hybrid system with an electric motor capable of adding an additional (albeit temporary) 20 horsepower and 148 pound-feet of torque.

While the preliminary version of the Mercedes G400d accelerated to 100 km/h in 6.4 seconds, its successor does so in just 5.8 seconds. The maximum speed remains unchanged at 209 km/h. This variant of the G-Wagen, not intended for sale in America, boasts approximately 140 pound-feet more torque than the G550, but lags behind in power by 81 horsepower. The new G450d is only half a second slower in acceleration compared to the G550.

Mercedes has not finished updating the G-Class, as a fully electric version will be introduced later this year, possibly without the «EQ» branding. In China, the old SUV is also sold with a four-cylinder gasoline engine called the G350, producing 255 horsepower and 273 pound-feet of torque. A hybrid version based on electric power seems to be not in the plans, although most other Mercedes models offer such an option.