BMW 5 Series Gran Turismo (2015) is 106 mm (4.17 inch) longer, 38 mm (1.50 inch) wider, 104 mm (4.09 inch) higher and has 30 liters (1.06 ft3) bigger cargo space than Buick Regal Sportback (2018).
Buick Regal Sportback (2018) is 388 kg (855 lbs) lighter than BMW 5 Series Gran Turismo (2015).