China's ongoing and recent air pollution issues are leading to swift rethinking of the country's transport policy.
After several months of choking smog engulfing its major cities, the country has finally imposed strict fuel economy standards in a bid to cut fuel use--and pollution.
Reuters reports the new standards were introduced Wednesday, and require automakers to boost fuel efficiency to an average of 34 mpg by 2015, and 47 mpg by 2020.
No fuel efficiency data from the last few years is available, but in 2009 the average stood at 30.2 mpg, an improvement over 2008 at 28.7 mpg.
For comparison, average fuel efficiency in the U.S. stood at 23.8 mpg in 2012.
China's new fuel-efficiency rules bring the country roughly into line with similar regulations in Europe and the United States. That gives global automakers a further incentive to develop even more efficient cars, since they'll be required by the world's single largest auto market.
Recently, record-breaking smog levels in some Chinese cities have posed a major hazard to health. People are frequently advised to stay indoors and avoid anything that may cause heavy breathing. High pollution levels have caused unrest and even sparked riots in certain parts of the country.
Much of the blame is laid on the country's reliance on coal power and coal-fired heaters, use of which rises over winter and traditionally leads to greater pollution.
China's coal habit is also one of the reasons electric cars are of debatable benefit there, despite their zero local emissions. However, poor electric car sales have seen the country shift its focus to hybrid vehicles instead.
The imposition of stricter standards will make life harder for some of the country's struggling domestic automakers.
Yale Zhang, head of Shanghai-based industry consultancy Automotive Foresight, says the new efficiency rules will be "tough for everyone, especially those small players as they will have to use more fuel-efficient engines and invest in hybrid technologies."
As well as cleaning up the country's vehicles, Chinese Premier Li Keqiang says the country will do more to curb China's increasing pollution problems.