BMW i8 (2016) is 22 mm (0.87 inch) wider and 598 kg (1,318 lbs) lighter than Mercedes X-Class (2018).
Mercedes X-Class (2018) is 651 mm (25.63 inch) longer, 526 mm (20.71 inch) higher and has 1006 liters (35.53 ft3) bigger cargo space than BMW i8 (2016).