BMW 4 Series (2014) is 15 mm (0.59 inch) wider than Mercedes C-Class (2016).
Mercedes C-Class (2016) is 48 mm (1.89 inch) longer, 80 mm (3.15 inch) higher, 140 kg (309 lbs) lighter and has 35 liters (1.24 ft3) bigger cargo space than BMW 4 Series (2014).