Strengthened Emissions Control for Petrol and LPG Vehicles

Implementation Details
Vehicle Emissions Standard
Helpful Tips
Download Area
Frequently Asked Questions


Studies have shown that poorly maintained petrol and LPG vehicles can emit up to 10 times more pollutants which worsen our roadside air quality.


To further improve our roadside air quality, from 1 September 2014 onwards, the Government implemented a new strengthened vehicle emissions control regime for petrol and liquefied petroleum gas (LPG) vehicles to enforce vehicle emission standards of carbon monoxide, hydrocarbons and nitrogen oxides.

Implementation Details

EPD deploys mobile remote sensing equipment at roadsides to identify petrol and LPG vehicles with excessive emissions without stopping them.


↑Real-time capture of emissions of vehicle in motion

↑ Emission test on a chassis dynamometer at a Designated Emission Testing Centre

If a vehicle is found to have exceeded its applicable emissions standard, the owner must have the vehicle tested and passed dynamometer-based emission test at a Designated Vehicle Emission Testing Centre (DVETC) within 12 working days.


Failure to comply with the requirement will lead to cancellation of the vehicle licence.

Vehicle Emissions Standard
The following types of vehicles running on petrol or LPG and manufactured in or after 1975 will need to meet the applicable vehicle emissions standard:

Petrol private cars
Petrol light goods vehicles

LPG / petrol taxis
LPG / petrol light buses


Helpful Tips

Proper maintenance is essential to prevent excessive emissions. It is a good practice to have your vehicle serviced regularly according to the schedule recommended by the manufacturer. If your vehicle is equipped with catalytic converters, you should replace them before the end of their service life.

Proper vehicle maintenance does not only reduce emissions, but also enhances driving performance and lowers fuel consumption

Samples of Catalytic Converters


Download Area
For Vehicle Owners:
Poster Leaflet Promotion Video
Poster Leaflet Promotion Video
Vehicle Exhaust Emission Limits    
Vehicle Exhaust Emission Limits    
For Vehicle Repair Mechanics:
Technical Guideline on Vehicle Emission Standards and Transient Chassis Dynamometer Test Technical Seminar Presentation (9-2014)
Technical Guideline on Vehicle Emission Standards and Transient Chassis Dynamometer Test (Chinese version only) Chassis Dynamometer Emission Test (Petrol and LPG Vehicles) Technical Seminar - Presentation (9-2014)(Chinese version only) Chassis Dynamometer Emission Test (Petrol and LPG Vehicles) - Lambda(Chinese version only)
For Operators of Designated Vehicle Emission Testing Centre (DVETC):
指定車輛廢氣測試中心實務守則(只提供英文版本) 指定車輛廢氣測試中心(只提供英文版本)  
Code of Practice for DVETC Application Form for DVETC  

Frequently Asked Question
1.  Is there any fee for getting the vehicle tested at a DVETC?
  • The owner needs to pay a fee of $620 for each test done at the DVETC.
2. How is the vehicle emissions standard set?
  • The vehicle emission standard is set according to the design standard which varies with the year of manufacture of the vehicle.  The limits are two times of that in the design standard.
3. My car has already passed the annual examination by the Transport Department (TD). Why does my car need to conduct additional tests?
  • Vehicles found to emit excessively by the remote sensing equipment must be tested at a DVETC.  This test CANNOT be replaced by TD's exhaust emission test in annual examination for licence renewal.
  • The exhaust emission test in annual examination for determining vehicles’ roadworthiness required by TD for annual licence renewal measures the concentration of carbon monoxide emitted by a vehicle (as well as hydrocarbons concentration in case of LPG vehicles) under idling status and cannot reflect the emission performance of a vehicle, in particular emission of nitrogen oxides, in real driving conditions when its engine is loaded. On the other hand, an excessively emitting vehicle identified by the remote sensing equipment has to conduct the emission test under real driving conditions simulated with the aid of chassis dynamometer to measure the emissions of nitrogen oxides, hydrocarbons and carbon monoxide for ascertaining whether the vehicle complies with its emission standards. Thus, TD’s exhaust emission test in annual vehicle examination is not equivalent to EPD's chassis dynamometer emission test.
  • Considering that excessively emitting vehicles accounted for only a small portion of LPG and petrol vehicle fleets, it is not recommended to incorporate the dynamometer emission test into TD’s annual examination, as it will significantly increase the test fee of annual examination and affect the entire fleet. Thus, only those vehicles found to emit excessively are required to conduct dynamometer emission test at the DVETC.
4. What should I do when I receive an Emission Test Notice (ETN)?
  • If you receive an ETN, it means your vehicle has been identified to be emitting excessively. You should repair your car promptly and take your vehicle to a DVETC for a dynamometer-based emission test before the deadline as stated on the ETN. You may contact EPD and apply in writing for extension of emissions test due date if you have practical difficulties in passing the emissions test as required on the ETN.

Enquiry Hotline: 3619 6610