Thanks to the addition of engine start-stop and recuperation technology, the common rail diesel three-door, five-door Sportback and Cabriolet variants benefit from major CO2 cuts of up to 20g/km or around 16 per cent, bringing output down to as little as 115g/km for three-door and Sportback versions.

The improvements apply immediately to all 140PS A3 2.0 TDI models equipped with six-speed manual transmission. They help to increase economy by at least 8mpg across the board, and to cut CO2 output by up to 20g/km or 16 per cent, boosting the three-door and five-door A3 2.0 TDIs from a combined total of 55.4mpg to 64.2mpg and cutting emissions from 134g/km to 115g/km. The Cabriolet benefits from an 8.1mpg increase to 61.4mpg and a 20g/km CO2 reduction to 119g/km, another lowest-in-class figure in the premium Cabriolet category.

In terms of company car taxation, this significant downward shift repositions the A3 2.0 TDI in the 13% BIK category, the movement from its original 18% position equating to a saving in annual tax liability of £373 for the three-door standard hatchback model, which will now cost a 40% tax payer £972.

Two fuel-saving systems
The start-stop system cuts engine power at idle when the clutch pedal is released and the gear lever is in its neutral position, and then restarts in just two-tenths of a second – more rapidly than any other comparable system – when the clutch is depressed.

Recuperation technology provides further fuel and CO2 savings by recycling a proportion of the wasted kinetic energy which is generated under normal braking and normally dissipated as heat, and storing this temporarily in the vehicle battery to reduce the engine load when the car subsequently accelerates again.