The Ecomotive offers big economy without compromising the Leon’s performance, but it doesn’t shout about its eco credentials, either. Many will be tempted by its running costs, and as usual SEAT has really undercut its rivals without making the hatch feel like a budget option. Ultra-efficient diesel cars such as the Ecomotive remain a strong choice for those who want a practical cheap-to-run car.

Is the new Leon Ecomotive a mile-munching hero or just a gimmick that claims to be green?

This latest eco effort from SEAT has the same power as the old model, with 104bhp, yet costs nearly £1,000 more. The good news is that there’s a host of extra technology promising to make it a very frugal family hatch.

Video: watch CarBuyer's video review of the SEAT Leon

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The new 1.6-litre TDI engine in the Ecomotive introduces common-rail injection – ensuring power delivery is smoother than before. It remains quiet and refined at motorway speeds, thanks to the longer gearing, and offers plenty of overtaking torque, with a useful 250Nm on tap from as low as 1,500rpm.

The efficient powerplant combines with aerodynamic styling extras, automatic stop-start, energy recovery and low rolling-resistance tyres, all of which give the Leon Ecomotive a CO2 figure of only 99g/km.

Fuel economy is impressive at 74.3mpg on the combined cycle. This means that not only is the Leon exempt from road tax, it also has a possible range of close to 900 miles on a single tank of diesel.

The stop-start system fires up virtually instantaneously, and only a slight vibration through the gearlever alerts you to this when pulling away.

On the outside, visual changes are minimal, with the boot badge and solid grille being the only clues to the Leon’s fuel-saving talents.

The rakish looks still make the SEAT a stylish alternative to rivals such as the VW Golf BlueMotion and Ford Focus ECOnetic, while a price tag of £16,840 means it’s cheaper, too.

This SE model is an additional £1,300 – but includes 16-inch alloys and cruise control, plus a leather-trimmed steering wheel, which adds a touch of class to the interior.