The A3 1.9 TDIe, which will be available in three-door and Sportback variants, uses a reworked version of the existing 1.9-litre TDI turbodiesel engine, offering 105bhp.
For the new model, the engine has been remapped with more of a focus on frugality rather than performance, and it also features revised gear ratios to boost economy.
The 1.9 TDIe will return a claimed average of 62.7mpg and emit 119g/km of CO2, enabling it to fall into the second lowest VED band. By comparison, the regular 1.9 TDI returns 57.6mpg and 129g/km of CO2.
A similar TDIe model will appear in the A4 range, and possibly in the A6.