Petrol that's kinder on the environment may not be kinder on wallets. Some consumers say they are concerned that higher standards will mean higher prices at the pump. While experts do concede that petrol will cost more, they do not think the hikes will be as sharp as is feared.

China's two leading oil refiners, Sinopec and PetroChina, have invested nearly 40 billion yuan to upgrade their products. The high cost of the upgrade is reflected in the higher gasoline price.

Yin xiaodong, Chief analyst of CITIC Securities, said, "Refining companies' costs have indeed risen, so consumers will have to pay more for gasoline meeting the Standard Three. By our calculation, the gasoline price will rise by 0.1 yuan per liter, which is a moderate rise. Of course, the price rise should reflect income differences in different places. We should consider the spending capacity of consumers."

Qiu Ciaofeng, analyst of China Merchants Securities, said, "I think the price will increase by 0.2 yuan per liter. The consumer will be feel the higher cost. But they are contributing to environmental protection."

Some experts believe that the next couple of months will be a sensitive period for price changes because of anticipated inflation. Moreover, time is needed to expand the standard upgrade nationwide, so the price hike is not likely to be seen in the short term.