Hyundai Motor affiliate Kia will have the greenest engine on the road when it launches its new Rio later this year.

The car will be available with a tiny three-cylinder engine which will have the lowest emissions around and can do an incredible 88 miles to the gallon.

At just 85g/km of CO2, the Rio will be cleaner even than a Smart at 86g/km and better than any hybrid. Only full electric vehicles can beat it.

“The Rio is a massively important car for us,” said Paul Philpott, the British head of Kia Motors Europe. “The car will give us a presence in the important B segment, one of the biggest in Europe, and, with its low emissions and seven year warranty, we will have a very enticing offer.”

When the new Rio arrives in the autumn, Kia will be pushing to increase sales in Europe from 20,000 a year for the old model to over 90,000.

The new Rio made its world debut in Geneva today and is part of a big product push for Kia this year which will also see the launch of the redesigned Picanto – also launched at the show – as well as the large Optima sedan which arrives in Europe at the end of the year.

The three-cylnder diesel Rio achieves its amazing emissions figures with the help of Kia’s ISG stop start system. The car will also be available with 1.4- and two-litre petrol engines as well as a 1.4-litre diesel. The Picanto will come with 100g/km 1.2-litre and three-cylinder, one-litre, 69g/km petrol engines.

Key to the success of the low-emission Rio will be price. Diesel engines normally attract a premium which is difficult to carry off in high volume, low margin cars.

Kia insiders say they can make the price stack up as advances in technology have reduced the cost of the new engine.