The range-topping Astra GTC comes with a 178bhp 1.6-litre turbo, a generous headline helping of power for a car of this size and price. But its 170lb ft of torque – the greater indicator of real-world performance – isn’t so generous. It means the Vauxhall comes up short next to the 178lb ft you get in a 1.4-litre ‘twincharged’ Scirocco, let alone the 222lb ft of a 2.0-litre turbo Renault Mégane coupé.
At our test track, the petrol-powered GTC’s showing was respectable, if unexceptional. In chilly and damp conditions, the car hit 60mph in a two-way average of 8.8sec and 100mph in 24.3sec. That 0-60mph time was a full second slower than Vauxhall’s claim but, betraying that shortfall in torque, it was two-tenths slower than the Scirocco 1.4 TSI we tested in the same conditions. Which may slightly undermine one of the key pillars of the GTC’s appeal for some: the delivery of a little bit of extra performance at a bargain price.
The 1.6 turbo engine is at its best high up in the revs. Through the middle of its range of operation, it feels a little strangled. But that’s only a minor, relative criticism. The engine’s good in-gear flexibility and throttle response make it easy to drive in everyday conditions.
Opt for the most potent 168bhp CDTi oil-burner, and the torque issue is certainly addressed; it boasts 258lb ft. Although this is not the most effervescent version of the GTC, it is refined and swift through the middle of the rev range, with decent throttle response for a powerplant of this kind, and quite a slick gearchange.
Away from the respective range-toppers on the petrol and diesel side, performance suffers, particularly with the entry-level 118bhp 1.4-litre petrol and the 108bhp 1.7-litre diesel. It’s certainly worth paying the premium for the extra shove to match the car’s style.