Mazda 6 (2016) is 130 kg (287 lbs) lighter than Opel Insignia Sports Tourer (2017).
Opel Insignia Sports Tourer (2017) is 49 mm (1.93 inch) longer, 17 mm (0.67 inch) wider, 63 mm (2.48 inch) higher and has 80 liters (2.83 ft3) bigger cargo space than Mazda 6 (2016).