The current national standard sets limits on sulphur content at 150 ppm and 350 ppm for gasoline and diesel respectively, although again some cities such as Beijing have successfully implemented higher standards (Ma et al., This is well above leading international benchmarks and what is needed to maximise the benefit of lower motor vehicle emission standards. Producing cleaner fuels requires the dominant domestic refineries to invest in costly new facilities. The practice of keeping gasoline and diesel retail prices below cost has hindered the feasibility of passing on the higher cost of cleaner fuels to consumers.