Half of China's cars will use cleaner fuels such as energy-efficient diesel, gas and bio-fuel by 2025, said an official Wednesday.

Renewable and low-emission energy sources will replace traditional gasoline to drive future Chinese autos, said Feng Fei, director of the industrial economics research department with the Development Research Center of China's State Council, at a seminar.

"Bio-fuel and hydrogen are the ultimate substitutes for fossil fuels," said Feng.

He added that fossil fuels will remain the major source of energy for Chinese cars by 2030, but cleaner forms of them will lead the future.

Meanwhile, Feng dismissed oil made from coal, which has developed rapidly in recent years, as a major alternate energy source for automobiles.

"The biggest problems of turning coal into oil are its low energy efficiency and high emission of carbon dioxide in the production process," said Feng.

Three to five tons of high-quality coal is needed to produce a ton of diesel, bringing the whole energy consumption to two to three times that of gasoline-driven cars, while the burning of the fuel emits 50 to 100 percent more carbon dioxide than that of gasoline.

With a larger reserve of coal than oil, China can make oil from coal as part of the country's strategic reserves, but large scale of production runs against China's goal to improve the efficiency of energy use and cut pollution, said Feng.

China has ascertained oil reserves of 24.8 billion tons and coal reserves of more than one trillion tons.

The Shenhua Group, China's top coal producer, has planned to invest in three projects from 2011 to 2012 to generate 10 million tons of oil from coal.

China is estimated to need 450 million tons of petroleum a year by 2020, with more than half to be imported.

(Xinhua News Agency October 26, 2006)