BMW 8 Series (G15) (2018) is 136 mm (5.35 inch) longer and 53 mm (2.09 inch) wider than GMC Terrain (2015).
GMC Terrain (2015) is 343 mm (13.50 inch) higher, 176 kg (388 lbs) lighter and has 1372 liters (48.45 ft3) bigger cargo space than BMW 8 Series (G15) (2018).