Audi A6 Allroad (2016) is 233 mm (9.17 inch) longer and 49 mm (1.93 inch) wider than GMC Terrain (2020).
GMC Terrain (2020) is 234 mm (9.21 inch) higher, 217 kg (478 lbs) lighter and has 1227 liters (43.33 ft3) bigger cargo space than Audi A6 Allroad (2016).