SEAT’s best-selling car, the sporty five-door Leon family hatch, is set to become even more appealing with the news that it is to benefit from the addition to the range of Volkswagen's hi-tech 1.4-litre TSI petrol engine.

Providing an important expansion of the existing, extensive Leon engine line-up – which ranges from a 1.6-litre petrol through to a 2.0-litre turbo – the TSI manages to pull off something of an engineering coup. Despite boasting fewer cubic centimetres than the 1.6 it is most closely allied to in the price list, it still manages to be markedly more potent, more frugal and more environmentally friendly.

It also manages to make the Leon significantly quicker in the 0-100 km/h dash, with a time that drops from 11.7 seconds to just 9.8 seconds.

This impressive piece of engineering works its magic by wringing extra efficiencies out of the 1.4’s seemingly modest capacity. Direct injection fuelling and an ultra-efficient single turbocharger boasting a more capable water-chilled (rather than air-chilled) intercooler enable the 1.4 TSI to deliver some truly impressive figures.

The power peak is on tap at an accessible 5,600 rpm, while the peak torque figure of 200 Nm is on offer across a particularly broad rev range: 1,750 rpm all the way up to 4,000 rpm, to be precise.

What these impressive statistics translate into on the road is an especially flexible drive, with a surprising turn of pace that belies the engine’s unassuming capacity.

For some, though, it’s sure to be the economy and emissions improvements that will seal the deal.

The all-important CO2 figure drops from 180 g/km to just 155 g/km.