Mercedes GL-Class (2014) is 648 mm (25.51 inch) longer, 211 mm (8.31 inch) wider, 411 mm (16.18 inch) higher and has 380 liters (13.42 ft3) bigger cargo space than Opel Ampera (2017).
Opel Ampera (2017) is 923 kg (2,035 lbs) lighter than Mercedes GL-Class (2014).
