BMW 5 Series (2014) is 156 mm (6.14 inch) longer, 221 mm (8.70 inch) higher, 123 kg (271 lbs) lighter and has 89 liters (3.14 ft3) bigger cargo space than BMW 8 Series (G14) (2018).
BMW 8 Series (G14) (2018) is 2 mm (0.08 inch) wider than BMW 5 Series (2014).