Ford Focus 1.0 Ecoboost Zetec

What is it?

A new, three-cylinder 1.0 litre turbocharged version of the Ford Focus, driven here in 123bhp form but also available with 99bhp.

This engine, whose cylinder block has barely the area of a sheet of A4 paper, arrives first in the Focus because its high-tech gadgetry (variable valve timing, miniature turbo, advanced electronics, direct fuel injection system) would make it expensive for the Fiesta.

The triple's efficiencies – which include super-efficient combustion, stop-start, a remarkably wide torque spread (with peak 125lb ft torque that overboosts to 148lb ft for 30 seconds to assist acceleration and passing manoeuvres), a six-speed gearbox and a 30kg weight saving over the front wheels – result in CO2 output of just 114g/km and combined fuel consumption of 56.5mpg for the six-speed version.

Five-speed figures are a little sharper, but that model loses a bit of performance against the six-speeder's 120mph top speed and 11.3sec 0-62mph acceleration. Both versions bring impressive tax advantages to business users.

What’s it like?

Even such promising paper figures don't prepare you for the driving experience. You barely hear the thing start, and it idles so smoothly you'd swear it had stalled. Your brain tells you such a small engine will need lots of revs off the mark, but it gets going easily because the combination of a tiny turbo, advanced electronic engine management and double variable valve timing give it amazing oomph in the low gears, even below 2000rpm (though the redline's 6700rpm).

It flows through the gears, always quiet but sounding more like a thoroughbred six than anything mainstream. You'll enjoy revving it, but you soon learn that changing up in the 3000s (aided by a smooth clutch and a slick six-speeder) delivers far better economy with pretty good performance.

Amazingly, the car is even long-legged. You've got to be indicating nearly 90mph before the tacho shows 3000rpm in sixth, and it can maintain this up hill and down dale. It is already clear, however, that like Fiat's TwinAir this Focus triple is an economy car for the willing. We turned 52mpg on a medium-fast, 80-mile trip through southern Spain, where another crew, not much faster, returned economy in the late 30s. You have to understand Ford's triple to make it sing for its supper.

Should I buy one?

This engine is a game-changer. It shows just how much life remains in petrol engines of a suck-squeeze-bang-blow persuasion. And that nowadays there is indeed a substitute for cubic inches.

Daft as it may sound, the tiny but super-advanced turbo triple – engineered in Dunton, England – confers a remarkable new layer of smoothness and refinement on the Ford's big-selling C-segment hatchback that is so obvious, so impressive and so refreshing that it leaves the four-cylinder models gasping.

Ford EcoBoost 1.0 Zetec 5dr

Price: £17,745; Top speed: 120mph; 0-62mph: 11.3sec; Economy: 56.5mpg (combined); CO2: 114g/km; Kerb weight: 1240kg (est); Engine: 3 cyls in line, 999cc, turbo, petrol; Installation: Front, transverse, FWD; Power: 123bhp at 6000rpm; Torque: 125lb ft (148lb ft on overboost) at 1500-4500rpm; Gearbox: 6-spd manual; Fuel tank: 55 litres; Boot: 316/1101 litres; Wheels: 7Jx16in; Tyres: 215/55 R16.