I have just driven the engine of the future. Not a plug-in hybrid or hydrogen fuel cell, but a good-old-fashioned petrol internal combustion engine. That doesn’t sound much like the future, I hear you cry, but the revolutionary technology about this internal combustion engine is its energy-efficient small swept volume with driveability boosted by a small, responsive turbo.

In the Fiat Bravo I was driving, it made 150bhp from 1368cc, equal to 110bhp/litre, exactly the same specific power output as a snarling, mid-90s Ford Escort Cosworth. Unlike that Cossie, though, the new ‘down-sized’ petrol engines have a different role – to provide smooth power and easy-going driving manners with lower fuel consumption and carbon emissions.

Fiat’s press materials claim performance from an engine size above with fuel consumption cut by 10 to 20 per cent. If all car-makers can do the same, Europe will make good progress towards its green targets.

Fiat markets the 150bhp 1.4 T-Jet as a madras-hot hatchback with a firm suspension, sports seats and dark-painted alloys, but it’s the precursor of an engine type that’s on its way in much bigger numbers in coming years. Also in the range is an 87bhp/litre, 120bhp 1.4, which, our spies tell us, will power next year’s Fiat 500 Abarth.

Similar charge-induction 1.4 and 1.6 engines boasting equal power to 1.6 and 2.0-litre engines are coming from nearly every other European car-maker — Citroen, Ford, Peugeot and Vauxhall.

There’s an industrial logic here. Economies of scale in engines are measured in millions of units compared to the hundred thousands for car bodies, so adapting a 1.4-litre block to suit three different slots in a model range is clever thinking. Of course, fitting turbos and intercoolers adds part and assembly costs, but as volumes go up, cost-per-piece comes down.

I enjoyed driving the T-Jet. It delivers power smoothly, without the rattle typical of a diesel, and it pulls from as low as 1200rpm with less hesitancy than an oil-burner.

It didn’t quite match a diesel for real-world fuel economy though. I saw 29mpg on the motorway, 22mpg around town. The official figures are 39mpg combined and 32mpg in the urban cycle, so it looks like a gentler driving style, swiftly changing-up to higher gears, is needed.

A back-to-back test on the same routes might determine if Fiat’s 120bhp 1.9-litre diesel, rated at 53mpg combined and 41mpg urban, is much better or worse in real-world driving. Maybe one for the road test team to examine?

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