Mercedes M-Class (2015) is 6 mm (0.24 inch) wider and 8 kg (18 lbs) lighter than Mercedes X-Class (2018).
Mercedes X-Class (2018) is 536 mm (21.10 inch) longer, 31 mm (1.22 inch) higher and has 470 liters (16.60 ft3) bigger cargo space than Mercedes M-Class (2015).