BEIJING, July 31 -- As China's global auto market continues to grow, so too does the nation's urgency to update emissions standards.

    So far, three emission categories have been rolled out across the country, with Beijing the only city currently employing the China 4 standard, which was introduced as part of plans to cut air pollution ahead of the Olympic Games last summer.

    Minivan brands like the Wuling Sunshine are bestsellers in rural areas and perfect for small firms on a limited budget. But as the majority only meet China 3 standard, which is equivalent to Euro 3, they may still pose a serious threat to the ecology of the countryside.

    "We can't prevent vehicle ownership increasing in rural areas but we can work on improving their environmental performance," said Zhang Jianyu, program manager for the Environmental Defense Fund China program. "We should be looking at consistent enforcement of emission standards for all cars."

    China 4 standard requires a 30 to 50 percent emission reduction on China 3 and, as of June 1, vehicles must pass an inspection to receive a green mark from local environmental protection bureaus. Cars and trucks without the mark will be barred from the capital from September, said the Ministry of Environmental Protection. Vehicles that fail get a yellow mark, while low-speed lorries, three-wheeled trucks, tractors and motorcycles cannot apply.

    Shanghai, the host of 2010 World Expo, is expected to apply the China 4 standard on newly registered light-duty gasoline vehicles, buses and municipal trucks this November but, as yet, it is still under discussion.

    "We should actively push forward the application of China 4," said Wang Jianxin, a professor at the department of automotive engineering at Tsinghua University in Beijing. "Although our industrial foundation is relatively weak and the new standard may place pressure on small and medium-sized enterprises, we should not lower our standards"

    He said the most practical fuel substitutes were ethanol gasoline, which has already been adopted in 10 provinces and cities, and biodiesel.

    (Source: China Daily)