Vauxhall is set to lead its class for combining power with low CO2 emissions with the latest version of the Astra Ecoflex.
Using a 130bhp version of the 1.7-litre CDTi diesel with stop/start technology - and with energy recuperation for the first time on a Vauxhall - it achieves 99g/km, equal to the Volkswagen Golf Bluemotion, Volvo C30 DrivE and Seat Leon Ecomotive.
However, the Vauxhall beats its diesel rivals for performance with a substantial 221lb-ft on tap.
Provisional CO2 emissions of 99g/km and fuel consumption of 76.3mpg are achieved on versions using 16-inch or 17-inch wheels. Prices are still to be confirmed, but are expected to start from a little over £20,000 on the road.
The new Ecoflex model falls into the 13% benefit in kind tax bracket - currently the lowest for diesel cars - and is eligible for a 100% first year writing down allowance, as well as a full discount on the London congestion charge.
When the driver takes his/her foot off the throttle, or applies the brakes, kinetic energy is collected and stored in the battery, allowing the alternator to shut down when there is sufficient charge to run ancillaries.
In addition, a clutch activates the air conditioning compressor only when it’s needed. Standard LED daytime running lights also reduce energy consumption compared with halogen lights.