Hi Shan,

That era Micra (the Micra was sold as the March in its native Japan) is the third-generation, if it’s a K12. That means the automatic was paired to a 1.2-litre engine, where it officially returned 42.8mpg, or 6.6 litres/100km. The manual model of the same car could reportedly achieve 46.2mpg, or 6.1 litres/100km. There’s not a huge amount in it, then, on economy, but the automatic in the K13 was not a great gearbox – it’s unrefined and it makes the car glacially slow. Find a manual, if you can and you don't mind driving manual.

Typically, it used to be that automatic gearboxes made a car thirstier and dirtier for emissions, but recent advances in automatic transmission technology means that most modern self-shifters are actually cleaner and greener than their manual gearbox counterparts.