Question & AnswerQ&A (DENR ADMINISTRATIVE ORDER NO. 51, S. 2003)
The official title is "Revised Emission Standards for In-Use Motor Vehicles Equipped with Spark-Ignition and Compression-Ignition Engines Except Motorcycles."
The purpose is to synchronize the emission standards of in-use motor vehicles equipped with spark-ignition and compression-ignition engines with the emission standards for new motor vehicles certified through a certificate of conformity issued by EMB.
The order covers in-use motor vehicles equipped with spark-ignition engines except motorcycles and those with compression-ignition engines.
A Spark Ignition Engine is an internal combustion engine in which the air/fuel ratio is ignited by a spark plug, such as gasoline, LPG, or CNG engines.
It is a pollution control device installed in a motor vehicle to control emissions of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).
The emission standards are 4.5% CO by volume at idle and 800 ppm HC as Hexane.
The standards are 3.5% CO by volume at idle and 600 ppm HC as Hexane or in accordance with the manufacturer's specification.
The standard is a light absorption coefficient of 2.5 m⁻¹ using a free acceleration test for both naturally aspirated and turbocharged engines.
The Department of Transportation and Communications (DOTC) and the Land Transportation Office (LTO) are responsible, conducted through Motor Vehicle Inspection Stations (MVIS) or authorized and accredited inspection centers.
Proof of compliance must be shown for renewal of registration and testing must be done within sixty (60) days prior to the registration date.
The test procedures described in Annexes B and C of DAO 2000-81 are used for measuring exhaust emissions of spark ignition and compression ignition engines.
It took effect fifteen (15) days from its publication in the Official Gazette or a newspaper of national circulation.