If the affordable price tag and penny-pinching engine aren’t enough to convince buyers, then Toyota iQ running costs impress further with low insurance grouping, long service intervals and road tax exemption for the manual version of the 1.0-litre engine.

The Toyota has been engineered with the planet, as well as your pocket, in mind. The upshot is the small three-cylinder 1.0-litre engine’s CO2 emissions are rock bottom, producing just 99g/km when fitted with the manual gearbox. It was the first petrol engine to do so and means a free tax disc for owners.

Particular attention has been paid to keeping Toyota iQ emissions down and fuel economy up, as all models come with low rolling resistance tyres and drivers are encouraged to go easier on the throttle by the on-board gearshift indicator light.

The 1.3-litre engine, introduced in July 2009, has higher emissions of 113g/km of CO2 but is still very frugal, averaging 59mpg.

Toyota iQ reliability shouldn’t be a problem: because the Japanese company is well known for building cars that owners can depend upon.

The iQ doesn’t skimp on interior quality and should wear well. Both tried and trusted engines are borrowed from Toyota’s popular Aygo and Yaris models.