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UN Regulation No. 51
Vehicle Noise Emissions

Uniform Provisions Concerning the Approval of Motor Vehicles having at least Four Wheels with regard to their Noise Emissions

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Revisions and Amendments
Series of Amendments and Supplements

Application of the Regulation

Contracting Parties applying UN R51

Related News and Information

18 Oct 2016 18 Oct 2016 | Indian government toughens emission norms for auto manufacturers India India Worldwide Harmonized Light Vehicles Test Procedure

This GTR prescribes a test cycle and test procedures to measure the emissions (including off-cycle) and fuel efficiency of light-duty vehicles. The GTR was adopted at the March 2014 session of the World Forum.

A supplemental "phase 1b" is underway to refine certain elements of the initial regulation. WP.29/AC.3 expects to consider a proposal for Amend. 1 to UN GTR No. 15 in November 2016 as result of Phase 1b activities.

A second phase is expected to address low ambient temperature, high altitude test procedures, and possibly durability and conformity issues.

A third phase would eventually include the addition of reference fuels, correlation across existing regional/national cycles, and introduction of emissions limits.

The latest draft version of the amended GTR is regularly updated by the WLTP informal working group.

The regulation is also supplemented by a gearshift calculation tool. WLTP Worldwide Harmonized Light Vehicle Emissions Test Procedure GTR No. 15 GTR No. 15, Uniform Provisions Concerning the Approval of Audible Warning Devices and of Motor Vehicles with regard to their Audible Signals Audible Warning Devices Audible Warning Devices and Signals UN Regulation No. 28 UN R28, Uniform Provisions Concerning the Approval of Motor Vehicles having at least Four Wheels with regard to their Noise Emissions Vehicle Noise Vehicle Noise Emissions UN Regulation No. 51 UN R51, Uniform Provisions Concerning the Approval of Vehicles with regard to the Emission of Pollutants According to Engine Fuel Requirements Together with R49, Regulation 83 addresses vehicle emissions. R83 covers emissions from all light vehicles (M1/N1) regardless of engine type and from heavier vehicles only if equipped with a gasoline engine. Under certain circumstances, R83 or R49 can apply to light vehicle CNG/LPG engines as well as to medium passenger and commercial vehicles (M2/N2) equipped with diesel engines. R83 also contains provisions specific to hybrid variations of the vehicles under its purview. Motor Vehicle Emissions Motor Vehicle Emissions UN Regulation No. 83 UN R83, Uniform Provisions Concerning the Approval of Passenger Cars Powered by an Internal Combustion Engine Only, or Powered by a Hybrid Electric Power Train with Regard to the Measurement of the Emission of Carbon Dioxide and Fuel Consumption and/or the Measurement of Electric Energy Consumption and Electric Range, and of Categories M1 and N1 Vehicles Powered by an Electric Power Train Only with Regard to the Measurement of Electric Energy Consumption and Electric Range CO2 Emissions/Fuel Consumption Carbon Dioxide Emissions and Fuel/Energy Consumption UN Regulation No. 101 UN R101, and Uniform provisions concerning the measures to be taken against the emission of gaseous and particulate pollutants from compression-ignition engines and positive ignition engines for use in vehicles Diesel/CNG/LNG Engine Emissions Diesel and CNG/LNG Engine Emissions UN Regulation No. 49 UN R49

21 Jun 2016 21 Jun 2016 | Indian vehicles are much louder than automobiles elsewhere in the world India India Uniform Provisions Concerning the Approval of Audible Warning Devices and of Motor Vehicles with regard to their Audible Signals Audible Warning Devices Audible Warning Devices and Signals UN Regulation No. 28 UN R28 and Uniform Provisions Concerning the Approval of Motor Vehicles having at least Four Wheels with regard to their Noise Emissions Vehicle Noise Vehicle Noise Emissions UN Regulation No. 51 UN R51
18 Apr 2016 18 Apr 2016 | Japan to apply UN R51 on vehicle noise from June 2016 Japan Japan Uniform Provisions Concerning the Approval of Motor Vehicles having at least Four Wheels with regard to their Noise Emissions Vehicle Noise Vehicle Noise Emissions UN Regulation No. 51 UN R51
4 Feb 2016 4 Feb 2016 | Adopted texts from the June WP.29 session now binding on Contracting Parties Uniform Provisions Concerning the Approval of Category L2, L4 and L5 Vehicles with Regard to Noise Three-Wheeled Cycle Noise Three-Wheeled Cycle Noise UN Regulation No. 9 UN R9, Uniform Provisions Concerning the Approval of Vehicles with regard to Safety-belt Anchorages, ISOFIX Anchorages Systems and ISOFIX Top Tether Anchorages Safety-Belt/ISOFIX Anchorages Safety-Belt and ISOFIX Anchorages UN Regulation No. 14 UN R14, Uniform Provisions Concerning the Approval of Vehicles with regard to the Protection of the Occupants of the Cab of a Commercial Vehicles Commercial Vehicle Cabs Commercial Vehicle Cab Occupant Protection UN Regulation No. 29 UN R29, Uniform Provisions Concerning the Approval of Motor Cycles with regard to Noise The proposal for the 04 series of amendments, adopted at the June 2011 Forum session, will be posted as Revision 2 to the regulation pursuant to the completion of administrative formalities. Motorcycle Noise Motorcycle Noise UN Regulation No. 41 UN R41, Uniform provisions concerning the measures to be taken against the emission of gaseous and particulate pollutants from compression-ignition engines and positive ignition engines for use in vehicles Diesel/CNG/LNG Engine Emissions Diesel and CNG/LNG Engine Emissions UN Regulation No. 49 UN R49, Uniform Provisions Concerning the Approval of Motor Vehicles having at least Four Wheels with regard to their Noise Emissions Vehicle Noise Vehicle Noise Emissions UN Regulation No. 51 UN R51, Uniform Provisions Concerning the Approval of Pneumatic Tyres for Commercial Vehicles and their Trailers CV Tires Commercial Vehicle Tyres UN Regulation No. 54 UN R54, Uniform Provisions Concerning the Approval of Two-wheeled Mopeds with regard to Noise Moped Noise Two-wheeled Moped Noise UN Regulation No. 63 UN R63, Uniform Provisions Concerning the Approval of Seats of Large Passenger Vehicles and of these Vehicles with regard to the Strength of the Seats and their Anchorages Coach Seat Strength Seat Strength and Seat Anchorages for Large Passenger Vehicles UN Regulation No. 80 UN R80, Uniform Provisions Concerning the Approval of Vehicles with regard to the Emission of Pollutants According to Engine Fuel Requirements Together with R49, Regulation 83 addresses vehicle emissions. R83 covers emissions from all light vehicles (M1/N1) regardless of engine type and from heavier vehicles only if equipped with a gasoline engine. Under certain circumstances, R83 or R49 can apply to light vehicle CNG/LPG engines as well as to medium passenger and commercial vehicles (M2/N2) equipped with diesel engines. R83 also contains provisions specific to hybrid variations of the vehicles under its purview. Motor Vehicle Emissions Motor Vehicle Emissions UN Regulation No. 83 UN R83, Uniform Provisions Concerning the Approval of Vehicles with regard to the Protection of the Occupants in the Event of a Lateral Collision This regulation applies to the lateral collision behavior of the structure of the passenger compartment of M1 and N1 categories of vehicles where the "R" point of the lowest seat is not more than 700 mm from ground level when the unladen vehicle plus 100 kg (i.e., the mass of a side impact dummy plus instrumentation) is at rest. Lateral Collision Protection Occupant Protection in Lateral Collisions UN Regulation No. 95 UN R95, Uniform provisions concerning the approval of vehicles with regard to specific requirements for the electric power train Electric Powertrain Vehicles Construction and Safety of Electric Powertrains UN Regulation No. 100 UN R100, Uniform Provisions Concerning the Approval of Passenger Cars Powered by an Internal Combustion Engine Only, or Powered by a Hybrid Electric Power Train with Regard to the Measurement of the Emission of Carbon Dioxide and Fuel Consumption and/or the Measurement of Electric Energy Consumption and Electric Range, and of Categories M1 and N1 Vehicles Powered by an Electric Power Train Only with Regard to the Measurement of Electric Energy Consumption and Electric Range CO2 Emissions/Fuel Consumption Carbon Dioxide Emissions and Fuel/Energy Consumption UN Regulation No. 101 UN R101, Uniform Provisions Concerning the Approval for the Production of Retreaded Pneumatic Tyres for Commercial Vehicles and their Trailers CV Retreaded Tires Retreaded Tires for Commercial Vehicles UN Regulation No. 109 UN R109, Uniform provisions concerning the approval of tyres with regard to rolling sound emissions and/or to adhesion on wet surfaces and/or to rolling resistance Tire Noise, Wet Adhesion, and Rolling Resistance Tire Rolling Sound Emissions, Adhesion on Wet Surfaces, and Rolling Resistance UN Regulation No. 117 UN R117, Uniform provisions concerning the approval of motor vehicles and their components with regard to the safety- related performance of hydrogen-fuelled vehicles UN Regulation version of the HFCV Global Technical Regulation. (For information on the development of this regulation, please see the GTR No. 13: HFCV regulation pages). Hydrogen Fuel Cell Safety Hydrogen fuel cell vehicle safety UN Regulation No. 134 UN R134, Draft new Regulation No. [13X] and 01 series of amendments concerning the approval of vehicles with regard to their pole side impact performance This regulation transposes Global Technical Regulation No. 14 into the type-approval system of the 1958 Agreement. The regulatory text (see the GAR pipeline) has been adopted and is undergoing the six-month waiting period before its finalization in June 2015. Pole Side Impact Pole side-impact protection UN Regulation No. 135 UN R135, Uniform provisions concerning the approval of vehicles of category L with regard to specific requirements for the electric power train This regulation (submitted as document WP.29/2015/69) was amended and adopted during the June 2015 session of the World Forum and is pending during the six-month administrative waiting period. Electric Motorcycle Safety Electric Motorcycle Power Train Safety UN Regulation No. 136 UN R136, Uniform Provisions Concerning the Approval of Vehicles with regard to the Seats, their Anchorages and any Head Restraints This Regulation applies to:
  1. Vehicles of categories M1 and N with regard to the strength of seats and their anchorages and with regard to their head restraints;
  2. Vehicles of categories M2 and M3 with regard to seats not covered by Regulation No. 80, in respect of the strength of seats and their anchorages, and in respect of their head restraints;
  3. Vehicles of category M1 with regard to the design of the rear parts of seat backs and the design of devices intended to protect the occupants from the danger resulting from the displacement of luggage in a frontal impact.

It does not apply to vehicles with regard to side-facing or rearward-facing seats, or to any head restraint fitted to these seats.

Strength of Seats Strength of Seats, Anchorages, and Head Restraints UN Regulation No. 17 UN R17, Uniform Provisions Concerning the Approval of Audible Warning Devices and of Motor Vehicles with regard to their Audible Signals Audible Warning Devices Audible Warning Devices and Signals UN Regulation No. 28 UN R28, and Uniform Provisions Concerning the Approval of Replacement Silencing Systems Replacement Silencing Systems Replacement Silencing Systems UN Regulation No. 59 UN R59
15 Jan 2016 15 Jan 2016 | India: After emission, NGT turns its gaze on vehicle noise rules ARAI and India Automotive Research Association of India and India Uniform Provisions Concerning the Approval of Audible Warning Devices and of Motor Vehicles with regard to their Audible Signals Audible Warning Devices Audible Warning Devices and Signals UN Regulation No. 28 UN R28, Uniform Provisions Concerning the Approval of Motor Cycles with regard to Noise The proposal for the 04 series of amendments, adopted at the June 2011 Forum session, will be posted as Revision 2 to the regulation pursuant to the completion of administrative formalities. Motorcycle Noise Motorcycle Noise UN Regulation No. 41 UN R41, Uniform Provisions Concerning the Approval of Motor Vehicles having at least Four Wheels with regard to their Noise Emissions Vehicle Noise Vehicle Noise Emissions UN Regulation No. 51 UN R51, Uniform Provisions Concerning the Approval of Replacement Silencing Systems Replacement Silencing Systems Replacement Silencing Systems UN Regulation No. 59 UN R59, Uniform Provisions Concerning the Approval of Two-wheeled Mopeds with regard to Noise Moped Noise Two-wheeled Moped Noise UN Regulation No. 63 UN R63, and Uniform Provisions Concerning the Approval of Non-Original Replacement Exhaust Silencing Systems (RESS) for Motorcycles, Mopeds and Three-wheeled Vehicles Motorcycle RESS Replacement Exhaust Silencing Systems for Motorcycles UN Regulation No. 92 UN R92
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Development of the Regulation

Pending Changes to UN R51

Latest Documents

5 Dec 2019
Comments on document ASEP II-14-09 (Review ASEP) | ASEP II-14-13
5 Dec 2019
UN R51: Comments on the consolidated 03 series up to Supplement 6 | ASEP II-14-12
5 Dec 2019
ASEP informal group noise database: all vehicles (public version) | ASEP II-14-11
See all 437 related documents

Latest Meeting Discussions

Working Party on Noise and Tyres | Session 71 | 28-31 Jan 2020
2nd Informal Working Group on Additional Sound Emission Provisions | Session 15 | 27-28 Jan 2020
Task Force on Vehicle and Tyre Noise Measurement Uncertainties | Session 2 | 28-29 Nov 2019
See more related meetings