Audi A6 Avant (2018) is 282 mm (11.10 inch) longer, 190 kg (419 lbs) lighter and has 216 liters (7.63 ft3) bigger cargo space than Mercedes GLC-Class (2015).
Mercedes GLC-Class (2015) is 3 mm (0.12 inch) wider and 191 mm (7.52 inch) higher than Audi A6 Avant (2018).