Audi has released its lowest emitting models – the A3 1.6 TDI – in hatchback, Sportback and Cabriolet bodystyles.

The efficient new engine will replace the 1.9-litre TDI engine currently found in the A3 TDIe and entry-level A3 Cabriolet.

Its headline figures are achieved in the hatchback and include 68.9mpg and emissions of just 109g/km with 104bhp and 184lb/ft of pulling power on tap.

Acceleration from 0-62mph takes 11.4 seconds and top speed is 121mph.

This is a sizeable improvement over the 1.9 TDIe which recorded 62.8mpg while emitting 119g/km with the same 0-62mph performance.

According to Audi’s figures the A3 Cabriolet 1.6 TDI will be able to achieve 65.7mpg while emitting 114g/km.

It accelerates from 0-62mph in 12.2 seconds and has a top speed of 118mph.

The improvements in efficiency have been aided by the addition of stop-start, which cuts the engine temporarily when stationary.

Recuperation technology recycles braking energy and uses it to charge the car’s battery, reducing the effects of a fuel-sapping alternator.

Prices will start from £17,485 for the hatchback, £18,025 for the Sportback and £20,645 in Cabriolet guise.

The A3 1.6 TDI will be available in Standard, Sport, SE and S-Line trim.