This 1.0-litre EcoBoost is more capable than a three-cylinder engine has any right to be. Not only does it make the Focus feel grown-up, it helps it perform as well in town as on motorways. The economy figures are just as impressive, while a price comparison with Ford’s diesels reveals it’s good value, too.

Putting a 1.0-litre three-cylinder engine in a Ford Focus doesn’t sound like the perfect recipe for motoring thrills. But this is Ford’s newest – and smallest – EcoBoost engine and it could well be one of the best in the current line-up.

The tiny engine, which has a footprint about as big as an A4 sheet of paper, is available with either 99bhp or 123bhp. Our car had the latter, but both engines feature direct injection and a minuscule turbocharger, and weigh only 97kg – that’s around 30kg lighter than the 1.6-litre petrol engine.

Look at the performance figures and you can see why Ford sees this engine as a replacement for the 1.6-litre. It takes the Focus from 0-62mph in 11.3 seconds, which is four tenths quicker than the bigger engine, and can manage 54.5mpg. By comparison, the 1.6 offers fuel economy of 44.1mpg.

While neither of the 1.0-litre’s figures can match those of Ford’s diesel models, the new EcoBoost has other talents. At idle, it’s almost completely silent, and under acceleration there’s a muted, deep three-cylinder warble that suits the grown-up nature of the Focus.

Most small engines like this require huge amounts of revs to pull away, but the 1.0 EcoBoost has no such problem. The only time you will be struck by its compact size is when you lift off in gear and discover that there’s very little engine braking to slow you down.

In corners, you’ll also notice that there’s less weight at the front of the car, which means it feels more agile and quicker to respond than any other Focus we’ve driven.

The most popular trim level will be the Zetec driven here. The kit list is decent, and includes air-con, DAB radio and cruise control. Although the price tag of £17,945 may sound expensive, it’s still £850 cheaper than the equivalent 1.6 TDCi diesel.

That means you’ll have to be a high-mileage driver before the diesel starts to make more financial sense than this excellent petrol engine.