THREE-cylinder, 1.0-litre turbocharged petrol engines have become a vital ingredient for car makers in powertrain line-ups for small and medium-sized models.

The advantage is simply that such engines are more fuel efficient but still deliver a decent road-going performance. They are also cheaper to buy and in the main much quieter than a diesel.

So for Spanish car maker SEAT and the medium-sized Leon it's perhaps a case of what kept you?

Now SEAT has borrowed an ultra efficient 113bhp 1.0-litre TSI powertrain from the Volkswagen family group engine warehouse and for the first time stuck it into the newly facelifted Leon to offer a sensible alternative to the rest of the model range's bigger petrol and engines.

And what a little corker it is even beating the sister 1.2-litre TSI version in terms of performance, economy and sheer driving pleasure.

Top speed for the 1.0-litre manual Leon is 123mph, 0 to 60 takes 9.6 seconds while the 1.2 model takes 9.9 seconds and tops out at 121mph.

With a DSG automatic transmission the 1.0-litre can stretch its legs even further, reaching a claimed 126mph.

The third generation Leon line up has six core trim levels - S, SE Technology, SE Dynamic Technology, FR Technology, FR Titanium and XCELLENCE but the 1.0-litre engine is being offered only in SE Technology grade.

So amidst the rush for out-and-out sporty hatchbacks and estates, the little three-cylinder Leon may well miss out in the stampede.

However, it shouldn't because the 1.0 TSI is an excellent powertrain ideally fitted to the Leon body, which in terms of platform and chassis remains much the same as its predecessor.

There's a choice of either a six-speed manual gearbox or a slightly dearer seven-speed DSG automatic box and both are available in either the five-door hatchback or estate.

The best one to go for in my book is the cheapest of the four - the manual hatchback which comes in at £19,235. If you want the same in the estate then that will cost £20,230 on-the-road.

For DSG versions then prices are £20,485 and £21,480 respectively and while the auto is noticeably smooth going up and down the gears, the six-speed manual is a real joy to use.

As such the Leon turns out to be comfortable and relaxing and in a way quite an undemanding car to drive.

With the manual box in the hatchback the Leon 1.0 TSI has a CO2 figure of 102g/km, a combined fuel return of 64.2mpg and an insurance group of 16 for good measure. Its company car tax banding is 19 per cent.

On a brief, hour-long first drive the Leon clocked in at a satisfying enough 56.8mpg over a variety of roads and surfaces across the Cotswolds and it was so quiet too - all too often three-cylinder turbocharged engine in such comparatively small cars tend to be noisy, particularly when accelerating hard.

Not so this Leon which is remarkably refined - far more so than its two main rivals in the three-cylinder brigade - the Ford Focus and Vauxhall Astra.

For the driver the light but nicely weighted steering makes it an uncomplicated and extremely pleasant family car to drive providing decent performance with decent fuel economy however it's driven.

In terms of looks the latest Leon doesn't look too different to the previous model but has a slightly larger grille, new look bumpers and lights - subtle yet different enough to give it a fresh look.

Inside with SE Technology trim there's plenty of standard kit such as a multi-media five-inch touch screen, LED daytime running lights, Bluetooth, USB and SD connectivity plus an emergency automatic braking system.

The Leon sits on 16-inch wheels and gives a comfortable enough ride, not quite as firm as say on its sister ship, the VW Golf.

The dashboard and central console have been changed a little making it much smarter and easier for the driver to use at a glance while the seats front and rear offer plenty of lumbar support.

Room in the rear seats means it's suitable for two full-sized adults - three is a squueze. Boot capacity is unaltered at 380 litres and with a 60/40 split rear seat there's extra space if needed.

There's plenty cubby holes inside which families always need and overall the interior is much smarter and more comfortable than its two main rivals, the Focus and Astra.

As with any new model in the Volkswagen empire the 1.0-litre Leon comes with plenty of safety features as standard, including seven airbags, stability control and automatic emergency braking.

Although the sporty Leon Cupra models along with the all-wheel-drive X-Perience versions will take all the plaudits for their out-and-out sporty performances, drivers looking for a more realistic slice of the new Leon action really do need to check out the 1.0-litre option.

For under 20 grand it's exceptionally good value for the money as a five-door hatch.