It's all right for the Chinese government to subsidize the sale of plug-ins and electric vehicles to help domestic automakers leapfrog the competition. 

And it's a good idea to offer subsidies of 3,000 yuan ($442) to consumers who buy fuel-efficient cars with an engine displacement of 1.6 liters or less, a policy that took effect on July 1.  

But it's wrong for the government to ignore conventional hybrids like the Toyota Prius or the Buick LaCrosse Eco-Hybrid. Using proven technology, these vehicles offer good fuel economy at a relatively affordable price. 

Yet, neither model is eligible for subsidies under Beijing's existing subsidy programs. 

In a country like China – which imports 51 percent of its oil and suffers from serious air pollution – the government ought to be doing whatever it can to encourage the sale of hybrids.   

Last week, I got a ride in a Buick LaCrosse Eco-Hybrid in Shanghai. GM had donated a fleet of 350 to be used as taxis during the World Expo, which runs from May to October.  

The cars are fitted with 2.4-liter Buick Ecotec engine and a Belt Alternator Starter System (BAS). It's a computerized stop-start system which turns off the gasoline engine when the car is idling or slowing down.  

The taxi driver told me that the car reduces fuel consumption by 15 percent compared with models that lack the stop-start technology.  

But that's not the only beauty of the car. I checked Shanghai GM's Web site and found that the car is sold for 269,900 yuan.  

True, a Buick LaCrosse Eco-Hybrid is still about 20,000 yuan more expensive than its gasoline version. But the price gap is not as wide as the cost differential between "pure" electric vehicles and gasoline-powered models.   

Take BYD Auto's F3 compact sedan. Its gasoline version is sold for less than 70,000 yuan while its plug-in version, the F3DM, carries a price tag of 170,000 yuan.   

Besides being cheaper, hybrids are technologically more mature than plug-ins and EVs.   

The BAS used in the Buick LaCrosse Eco-Hybrid is a proven technology. Likewise, Toyota has sold more than one million Prius hybrid sedans worldwide since it was launched in 1997.  

By contrast, plug-ins and EVs are untested products that can't be used without charging stations. Hybrids have earned a niche in the market for 'green'  transportation. It's time for Beijing to recognize that.