By now, the idea of a large vehicle powered by a puny engine should have lost some of its novelty. But Opel's 1.5-litre Insignia - a car nearly as big as a BMW 5-series - still manages to surprise with its fluidity and poise.

Putting out 165hp and 250Nm, the 1.5-litre turbocharged petrol unit is anaemic when compared to its 260hp/400Nm 2-litre counterpart. But on the road, the smaller power plant puts on a creditable display, arriving at 100kmh in 9.4 seconds and peaking at 218kmh.