Small cars have always been big business in the car world, but now they are huge.

The downsizing move started at the end of the last decade but, with economies shrinking and wallets tightening, some analysts are predicting that superminis will account for one in three of all European car sales by 2014.

All this is surprisingly good news for car buyers, as supermini specification continues to rise to meet the aspirations of people who want to downsize with no intention of moving downmarket.

Kia, a rising star of a carmaker, has always been good at packing equipment into its compact cars but with its build quality now streets ahead of its early days, the fixtures, fittings and feel of the new Rio start to look really impressive.

Longer, wider and lower than the model it replaces, the overall aura of the Rio is of a European, if not Germanic-built, hatchback, with a solid ride, taut handling and a clean, quality feel about the interior.

The three-cylinder instrument cluster and dashboard is clearly laid out, with a new set of toggle switches on the centre stack. Seats are large, firm and supportive and add to the solid feel.

Powering the test car was a 1.4-litre, four-cylinder diesel engine, delivering 89 horsepower. The car carried the EcoDynamics badge, which involves a package of fuel-saving, CO2-reducing measures including ‘intelligent stop and go’ engine technology, low rolling resistance tyres, a drag-reducing front grille, gearshift indicator and rear spoiler.

Linked to a six-speed manual gearbox, on paper it offers the prospect of up to 70mpg in day-to-day driving, but over almost 500 miles of urban crawl and motorway driving I could only manage 60.7mpg.

Another of the engine choices is a 1.1-litre, three-cylinder, turbodiesel, which Kia claims has lower fuel consumption and CO2 emissions than any other non-electric car on sale in the world.

Competing against the big hitters in the supermini market, such as the Ford Fiesta, Renault Clio, Volkswagen Polo, Peugeot 207 and Vauxhall Corsa, the Rio comes armed with a wide range of safety equipment including electronic stability control, which detects when road conditions or driving style might cause the car to go out of control, and stabilises it by braking one or more wheels, reducing engine torque, or both.

This is linked to anti-lock brakes with electronic brake force distribution and emergency brake assist so that maximum stopping power is always guaranteed. It also comes with twin front, side and curtain airbags, plus seatbelt pre-tensioners and load limiters for the front occupants.

The new Rio also includes hill-start assist to prevent the car momentarily rolling backwards when pulling away up steep gradients.

And while the Rio might be a small car, it still comes with the biggest warranty in the business.

Price: £14,195 Insurance group: 7 (1-50) Fuel consumption (Combined): 70.6mpg Top speed: 107mph Length: 404cm/159in Width: 172cm/67.7in Luggage capacity: 288l/10.1 cu ft Fuel tank capacity: 9.4 gallons/43 litres CO2 emissions: 105g/km Warranty: 7 years/100,000 miles