Very small car engines – which we’ll define as those up to one litre, or 1000cc – have been making a comeback in recent years.

Until the 1970s they were all over the place. Back then, cars were much lighter than they are now (mostly because they weren’t weighed down with safety equipment) and expectations of performance were low, so a one-litre engine provided all the power most people needed.

As cars became heavier and people wanted to go faster, the average size of an engine increased, to the point where one-litre units became extremely rare.

But then came concerns about fuel economy and exhaust emissions. Manufacturers realised that by ‘down-sizing’ (building smaller engines and turbocharging or supercharging them) they could offer the same power as a larger engine along with – on paper, at least – much better economy and CO2 figures.

The CO2 issue was particularly important, because the less of it the car produced on the official test, the less Vehicle Excise Duty the owners would have to pay.

Eventually, things got to the point where one-litre engines became quite common. There are no fewer than 21 mainstream manufacturers currently offering them in the UK, and over the next few minutes you’ll see who they all are.