The Mii Ecofuel, which is SEAT’s first CNG model, will offer average consumption of 2.9 kg CNG/100 km, giving it running costs that are approximately half those of a Mii with a petrol engine, as well as a best-in-class CO2 figure of 79g/km.

The 1.0-litre, 68PS engine is based on the three-cylinder petrol unit found in the Mii (with 60PS and 75PS outputs), but has been specifically developed for CNG operation and offers maximum torque of 90Nm at 3,000rpm.

Despite being specifically engineered to run on CNG, the Mii Ecofuel engine can also run on unleaded petrol. With a full CNG tank (11 kg), the Mii Ecofuel has a range of up to 240 miles; the reserve petrol tank (10l) extends the range by up to 140 miles. This means that, with a full tank, a total range of up to 380 miles is possible.

‘The new SEAT Mii Ecofuel now makes environmentally friendly CNG technology affordable for all,’ said James Muir, president of SEAT SA. ‘Its attractive starting price and exceptionally low consumption and emissions figures make the Mii Ecofuel one of the most interesting and sensible choices available – even for high-mileage drivers.’

Initially, SEAT will introduce the Mii Ecofuel in markets such as Germany, where it will have an entry price of €12,050, as well as Italy, Austria, Switzerland, the Netherlands, Sweden and the Czech Republic where there is a clear demand for CNG fuelled cars and the infrastructure to support it.

SEAT adds that there are currently no plans to sell the Mii Ecofuel in the UK, owing to lack of supporting infrastructure.