Audi S8 (2016) is 449 mm (17.68 inch) longer and 135 mm (5.31 inch) wider than Opel Astra Sports Tourer (2014).
Opel Astra Sports Tourer (2014) is 67 mm (2.64 inch) higher, 1519 kg (3,349 lbs) lighter and has 35 liters (1.24 ft3) bigger cargo space than Audi S8 (2016).
