BMW 8 Series (G15) (2018) is 345 mm (13.58 inch) longer, 115 mm (4.53 inch) wider and has 120 liters (4.24 ft3) bigger cargo space than Opel Ampera (2017).
Opel Ampera (2017) is 98 mm (3.86 inch) higher and 267 kg (589 lbs) lighter than BMW 8 Series (G15) (2018).