Vauxhall Astra ecoFLEX

The biggest problem for this Astra is the Golf BlueMotion. While the Vauxhall has more power, it costs more to buy, isn’t likely to hold on to its value as well and isn’t such an accomplished all-rounder. Even so, the new eco Vauxhall will cost very little to run on a daily basis, is good to drive and very easy to live with. It’s a solid performer.

This road tax-exempt Astra is cheaper to run than the average supermini. The 1.7-litre CDTI diesel is the latest entry into Vauxhall’s super-frugal ecoFLEX range, and grabs the headlines with claims of 76.3mpg economy and 99g/km CO2 emissions.

Trouble is, it’s priced from £20,725 – that’s £1,865 more than the VW Golf BlueMotion, which posts similar figures and is our current favourite road tax-free compact hatchback. Can the Astra justify its higher price?

As with all eco models, the Vauxhall uses a simple but effective array of tweaks to cut emissions and boost efficiency. There’s a stop-start system, as well as some subtle aerodynamic changes – with the ride height lowered by 12mm and an active grille shutter. You get low-rolling-resistance tyres and a brake energy recovery system, too.

Changes have also been made under the bonnet. A new engine management system, turbo and reduced friction have allowed Vauxhall to extract an extra 4bhp from the 1.7-litre CDTI – it now produces 128bhp and 300Nm of torque. That’s impressive when you consider that the Golf BlueMotion’s 1.6-litre diesel delivers 104bhp and 251Nm respectively.

On the road, there’s plenty of urge. Eco models can often labour in town and feel as if they’re over-geared, but the Astra is impressively strong with decent response and a wide power band. The engine is helped by a slick and precise six-speed manual gearbox.

The stop-start system is fuss-free, too. It restarts quickly – even from cold. Other features include a shift indicator to tell you when is the best point to change up or down gear.

But the engine could be smoother. It sounds rattly from start-up and is noisy under power. The ride is a bit on the stiff side, too, although the pay-off is precise handling and little body roll in corners.

Handsome though it is, the Astra blends into the background in UK traffic. But the cabin feels modern and attractive, with some high-quality plastics and well judged red mood lighting.

Should you buy this Astra ecoFLEX? We’d still go for the better-value Golf BlueMotion. Even more worrying for Vauxhall and VW is that Ford will launch a Focus ECOnetic in June with 80mpg and 89g/km.