Modern cars can reduce fuel consumption by more than 2.5 percent just by adding a piece of software to the engine computer, a Dutch scientist has found in a university research project together with Ford.

Eindhoven University of Technology scientist John Kessels said on Wednesday he had managed to reach optimal engine performance more often by adding a piece of software to a car's computer.

Kessels' software dynamically switches the dynamo, which charges the car battery, on and off.

"Just by adding a piece of software and a simple cable, cars can save 2.6 percent of fuel consumption," he said.

The software is not proprietary to Ford and can be used in any car with an engine computer, he said. In general, this applies to most modern cars.

A more significant savings of 5 percent to 6 percent can be achieved if the car engine were to be switched on and off, but this would require adjustments to the car engine, he said.

Fuel efficiency is a major topic for car makers as governments struggle to reduce greenhouse gas emissions, which contribute to global warming.

Earlier on Wednesday, the European Commission unveiled a broad strategy to cut carbon dioxide emissions from cars, proposing binding limits that automakers say will threaten jobs and lead to big price increases for consumers.

The European Union executive, a world leader in fighting climate change, is targeting car companies to help meet goals to reduce emissions under the Kyoto Protocol.