Hyundai i30 (2020) is 9 mm (0.35 inch) wider and 119 kg (262 lbs) lighter than Mercedes B-Class (2018).
Mercedes B-Class (2018) is 53 mm (2.09 inch) longer, 102 mm (4.02 inch) higher and has 106 liters (3.74 ft3) bigger cargo space than Hyundai i30 (2020).