The new Ford Mondeo engine is cleaner and more powerful.

Ford is very proud of its Duratec HE four-cylinder 1.8 and 2.0-litre petrol engines, freshly developed for the new Mondeo - and rightly so.

They are clean, frugal and powerful, and owe at least one aspect of their design to alternative-fuel engines developed for countries like Brazil that burn ethanol.

Petrol engines have been modified to run on ethanol-blended petrol for years by a number of major manufacturers including Ford, Fiat and Renault.

In countries where there’s a plentiful supply of sugarcane, ethanol provides an economic alternative to petrol, reducing emissions at the same time. But engines have to be recalibrated to run on the fuel. And because valves and valve seats wear more quickly in these engines, Ford began to develop special materials to tackle the problem.

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Robust valvetrain is designed to avoid any drop-off in efficiency.

he work has paid unexpected dividends as the Duratec has the tappet clearances of its mechanically-operated valvetrain set for life when the engine is built. According to Georg Festag, a senior engineer on the Duratec engine, the components are so robust that no recession of the valves should ever take place. Hence there is no drop-o ff in efficiency or increase in noise.

The Duratec is one of the new breed of engines already meeting the tough EU4 emissions regulations arriving in 2005. But to make engines qualify, powertrain engineers have to pull out all the stops.

The Duratec has an electrically-heated thermostat. Festag explains: “We run the engine at 100deg C at part load and 85deg C at full load by using a small electric heater in the core of the wax thermostat. Doing that gives us between one and three per cent improvement in fuel consumption.” ‘Tumble flaps’ close the inlet tracts by up to 70 per cent, causing a tumble motion of the intake air, which improves fuel-air mixing considerably at light throttle openings.

Manifold features 'tumble flaps' that help improve fuel-air mixing.

I also allows retardation of ignition during start-up. This increases exhaust gas temperature, bringing a ‘close-coupled’ cataytic converter to operating temperature more quickly. Without these tumble flaps improving the fuel-air mixture, the spark retards too far and the engine misfires.

It’s not all emissions regulations, though. The Duratec engineers have still found time to remember the fun aspects of driving too.

Like other Fords including the Puma, Cougar and Fiesta, the Mondeo’s Duratecs have a tuned intake manifold specifically designed to feed a sporty induction noise back to the driver. A bell-mouthed pick-up supplies cold air to a tuned resonator in the wheel arch, while ‘organ pipes’ produce the kind of sound we like to hear when the engine is working hard.