Beijing introduced new vehicle fuel standards on Tuesday, which represent another way to ensure the "green Olympics" that China has promised.

Under the new standard, gasoline and diesel sold at all outlets in the capital city must meet the new China IV standards, which are equivalent to the European Union's Euro IV standards, according to Du Shaozhong, deputy director of the Beijing Environment Protection Bureau.

The China III standards, equivalent to their EU counterparts, have reduced sulphur dioxide emissions from automobiles by 2,480 tons annually since they took effect at the end of 2005, according to official statistics.

The new standards would cut sulphur dioxide emissions by another 1,840 tons, said Feng Yuqiao, the head of the motor vehicle department of the Beijing Environment Protection Bureau.

Feng noted that several thousand of Beijing's nearly 20,000 buses had begun using the cleaner fuels in 2007.

The quality of refined oil of the city is satisfactory. An inspection in the fourth quarter of last year found that 97 percent of the refined oil supplied by automobile distributors met the national standard.

There are an estimated 3.1 million motor vehicles in Beijing with about 1,000 to 1,200 vehicles added to the city's congested roads every day.

Beijing faces tremendous pressure to improve its air quality ahead of the 2008 Olympic Games. Under the Olympic host city's ambitious "blue sky" plan, it must have 70 percent of the days in 2008 up to standard.

In 2007, Beijing narrowly achieved the goal of 245 "blue sky" days.

Motor vehicle exhaust is among the top pollution causes. Earlier reports suggested that about 40 percent to 50 percent of the major pollutants in Beijing's air -- nitrogen oxides, carbon monoxide and particulate matter -- come from vehicle exhaust emissions.

Numerous measures have been undertaken to get Beijing residents out of their cars and into public transport, including boosting the availability of public transportation with a new North-South subway line and slashing fares.