Buick Regal TourX (2018) is 488 mm (19.21 inch) longer, 75 mm (2.95 inch) wider, 44 mm (1.73 inch) higher and has 300 liters (10.59 ft3) bigger cargo space than Opel Ampera (2020).
Opel Ampera (2020) is 25 kg (55 lbs) lighter than Buick Regal TourX (2018).