China has vehicle fuel economy and emissions standards for both heavy-duty and light-duty vehicles.
"The legal foundations for China’s vehicle emission control regulations and programs, including compliance programs, are in China’s Air Pollution Prevention and Control Law. The law requires that emissions from all motor vehicles and vessels must not exceed the regulated limits, prohibits any entity from producing, selling or importing vehicles that do not comply with emissions standards, and prohibits vehicles that fail to meet in-use emission standards from operating on the road."
"VECC-MEP estimates that nationwide, about 10-20% of vehicles do not pass their first I/M inspection, but there is no data on how many vehicles are being tested every year."
(http://www.transportpolicy.net/index.php?title=China:_Compliance_and_Enforcement)
"In 2011, a third phase to the fuel economy standard has been introduced, targeting fuel
consumption of 5L/100km by 2020, which translates to an estimated of 120g/km CO2
emissions and adding corporate average fuel consumption target to the original
vehicle-based standard." - for light-duty vehicles (http://www.unep.org/transport/gfei/autotool/case_studies/apacific/china/CHINA%20CASE%20STUDY.pdf) The limit in 2015 was 6.9L/100km.
Emissions standards for other types of pollutants from light-duty vehicles can be found here: http://www.transportpolicy.net/index.php?title=China:_Light-duty:_Emissions
Heavy-duty vehicles (>3.5 metric tons) fuel economy standards vary according to weight from 13 to 45.5 l/100km, based on Phase II standards, applying from 2014. (exact values: http://www.transportpolicy.net/index.php?title=China:_Heavy-duty:_Fuel_Consumption)
Heavy-duty vehicles (>3.5 metric tons) emissions standard China V has been adopted in 2016. Standards for different pollutants can be found here: http://www.transportpolicy.net/index.php?title=China:_Heavy-duty:_Emissions
Fuel consumption standards for motorcycles and mopeds are 8l/100km for two-wheelers and 9l/100km for three-wheelers
Since January 2016, Phase IV standards set a fleet average target of 5.0 L/100km for new passenger vehicles sold in 2020.
In June 2019, Phase V is in discussion, which would result in new standard of 4L/100km in 2025