Cadillac ATS (2014) is 250 mm (9.84 inch) longer and 20 mm (0.79 inch) wider than Mercedes B-Class (2018).
Mercedes B-Class (2018) is 137 mm (5.39 inch) higher, 109 kg (240 lbs) lighter and has 105 liters (3.71 ft3) bigger cargo space than Cadillac ATS (2014).