BMW i8 (2016) is 1000 kg (2,205 lbs) lighter than Rolls-Royce Phantom (2018).
Rolls-Royce Phantom (2018) is 1300 mm (51.18 inch) longer, 75 mm (2.95 inch) wider, 363 mm (14.29 inch) higher and has 384 liters (13.56 ft3) bigger cargo space than BMW i8 (2016).