Geneva 2008: Hyundai i-Blue

[Overheat]

Using compressed natural gas (CNG) in cars is nothing new - it's been a popular fuel in many mainland European countries for years - but it has never taken off in the UK.

Shame - the Hyundai i10 blue CNG concept demonstrates clearly CNG's possibilities. It emits just 65g/km of carbon dioxide from its three-cylinder engine, little modified from the standard petrol-drinking Hyundai-Kia unit. And it can be refuelled at little expense from a domestic gas supply, too.

The concept also highlights further changes Hyundai is proposing for its production cars. The blue-line models have stop-start, cutting the engine when idling and automatically restarting, lowered suspension, low rolling-resistance tyres, modified gearboxes and other measures to improve aerodynamics. These measures have been applied to another i10 blue with the 75bhp 1.1-litre diesel engine, a model returning 95g/km compared to the standard-production version's already low 114g/km, and the i30 blue 1.6 (106g/km, compared to the standard car's 125g/km).

Though the i10 diesel is economical and tax-friendly, Hyundai is not planning to bring it to the UK - it only delivers 5mpg more than the petrol, but would cost £700 more.