New 99g/km CO2 Vauxhall Astra EcoflexFree car tax and a claimed 76.3mpg from new Astra

29 June 2011

Vauxhall Astra Ecoflex

The Vauxhall Astra Ecoflex qualifies for free car tax and avoids the London congestion charge

Vauxhall has announced a new 99g/km CO2 Ecoflex version of the latest Astra.

The Vauxhall Astra Ecoflex brings a raft of technological improvements to the 1.7-litre CDTi turbodiesel engine to deliver much-improved fuel economy of 76.3mpg (claimed), as well as more power.

How does the latest Vauxhall Astra compare to its rivals? Find out by reading our medium car reviews.

Vauxhall Astra Ecoflex 99g/km: engine changes

A significant number of changes have been made to bring the 1.7-litre turbo diesel Astra's emissions down below the 100g/km CO2 mark.

A new engine management system allows a reduced compression ratio, while new injectors are now capable of eight injections per cycle at 1,800 bar – which should also benefit refinement. A variable geometry turbocharger provides better boost-pressure control.

Furthermore, internal changes mean reduced friction, sensors in the glow plugs increase the accuracy of combustion, and there is even a bypass system for the oil cooler. This hastens the warm-up time, one of the least efficient periods of any car’s operation. A stop-start system is fitted, too.

Learn more about efficient car developments like stop-start systems in our guide to green car technologies.

Vauxhall Astra Ecoflex

New technology makes the Ecoflex the most efficient Vauxhall Astra yet

Ecoflex efficiency improvements

On top of this, the Astra Ecoflex has a ‘friction-reduced’ six-speed manual gearbox, specifically matched to the recalibrated engine. There is a shift indicator in the instrument cluster to help you drive in the most fuel-efficient way.

Another major step comes with the introduction of a brake-energy recuperation system, harnessing kinetic energy that would otherwise be wasted when braking. This is then used to charge the battery, reducing demand on the alternator – another traditionally inefficient area of the car. Similarly, the air conditioning compressor is only operated when required.

The final improvements come with the aerodynamics. Low-rolling resistance tyres are a given – although you do get a choice of 16- and 17-inch alloy wheels depending on trim level. There's also a 12mm reduction in ride height, plus an active shutter that closes the grille to smooth airflow whenever cooling requirements allow.

Want to learn how to drive more economically? Watch our eco driving videos and read our tips.

More power and better economy

Vauxhall Astra Ecoflex

Vauxhall is claiming fuel economy of 76.3mpg for the new Astra Ecoflex

The outcome of all this is a 128bhp 1.7-litre turbo diesel Astra that emits 99g/km CO2 and manages a claimed 76.3mpg.

The power output is actually a 5bhp increase over the previous (123bhp) version of this engine, despite a 20g/km CO2 reduction.

And 128bhp is also a good deal more than the 103bhp the VW Group rivals can muster, including the Golf BlueMotion. This, together with 221lb ft of torque (pulling power), bodes well for performance – although details have not yet been announced.

The new 99g/km Vauxhall Astra Ecoflex will be available in Exclusive, SE and SRi specifications when it goes on sale later this year. Pricing will be confirmed nearer the time.

How economical is your car? Use the Which? Car fuel economy calculator to find out.


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