What is it?
It’s surprising how a better engine can improve the whole of a car’s character.
The diesel-engined Vauxhall Astra Sports Tourer has always seemed like an inoffensive, workaday sort of machine when powered by the long-serving 1.7 and 2.0-litre diesels, but it was nothing out of the ordinary.
However, the arrival of a new aluminium-blocked 1.6-litre unit – which matches the power and torque of some 2.0-litre versions, complies with Euro 6 emissions and slashes fuel consumption by 10 per cent – has given the car a new level of responsiveness and refinement.
The engine in our test car, whose punchy 134bhp at 4000rpm is accompanied by a healthy 236lb ft at 2000rpm, is part of a downsizing move that will run across the whole of Vauxhall’s four-cylinder petrol and diesel engine range.
The Hungarian-made 1.6 CDTi is the latest piece in Vauxhall’s plan to create three all-new engine families and reveal 23 new models by 2016.
What's it like?
What impresses you about the 1.6 diesel in the Astra is its smoothness and quietness. It feels free-revving for a diesel, but you still get the impressive low-end thrust for which the previous, less-refined units were known.
Vauxhall claims a 0-62mph time of 9.7sec and a top speed of 125mph, both of which feel within the engine's remit.
On a long motorway haul, taken as quickly as traffic would allow, the car returned 52mpg and offered a touring range of 580 miles.
In Tech Line trim, with cloth seats and running on 17-inch wheels, the test Sport Tourer cornered and steered very well, and coped impressively with abrupt bumps and potholes.
The cabin feels suitably spacious and is comfortable over even long distance, which combined with the car's pliant ride makes the Vauxhall a pleasant daily companion.
Drop the rear seats and you're offered a substantial 1550 litres of storage space too – larger than that of the equivalent Ford Focus estate.