Acura RLX (2014) is 139 mm (5.47 inch) longer, 124 mm (4.88 inch) higher, 140 kg (309 lbs) lighter and has 2 liters (0.07 ft3) bigger cargo space than BMW 8 Series (G15) (2018).
BMW 8 Series (G15) (2018) is 12 mm (0.47 inch) wider than Acura RLX (2014).