Explanatory document on proposed amendments to UN R168 to enable real driving emissions testing of hydrogen internal combustion engine vehicles. The work-based approach replaces the CO-based moving averaging window methodology currently inapplicable to hydrogen-fuelled vehicles. Engine speed and torque data replace carbon monoxide to define window size and calculate the RDE/WLTP work ratio. Testing of a light commercial vehicle demonstrates the methodology’s practical applicability under regular and severe driving conditions, with results processed through independent post-processing tools.
Proposal to establish uniform provisions for approval of non-original replacement and identical brake pads, drum brake linings, brake discs, and brake drums for vehicles of category M₁, N₁, and N₂ between 3.5 and 5 tonnes maximum mass. The regulation applies brake emission testing procedures and particle emission limits by vehicle category and powertrain technology, with PM10 limits ranging from 3 mg/km for PEV vehicles of categories M₁ and N₁ to 11 mg/km for N₁ Class III and N₂ vehicles. Brake parts must be assigned to families based on characteristics including calliper type, axle location, friction material formulation, disc or drum material, brake disc surface form, pad surface area, and drum diameter. Approval requires testing of a family parent brake assembly and includes conformity of production requirements with annual sampling and statistical verification procedures.
Proposal to establish a UN Regulation for laboratory measurement of brake particle emissions from vehicles of categories M2, M3, N2 and N3 using friction braking systems. The regulation specifies test procedures including brake bedding and brake emissions measurement using the Worldwide Harmonized Heavy Duty Vehicles Brake Cycle, defines brake emissions groups and representative configurations for testing, establishes emission limits by vehicle category and powertrain technology (though limits marked as ‘not yet specified’ in the provided draft), requires conformity of production testing with statistical verification procedures, and sets technical requirements for brake dynamometer systems, brake enclosure design, sampling tunnels, cooling air conditioning, particulate matter and particle number measurement systems, and data acquisition.
Final status report on development of a new UN GTR for laboratory measurement of brake particle matter (PM) and particle number (PN) emissions from heavy-duty vehicles. The GTR introduces brake emissions groups based on fundamental design and performance characteristics, defines brake group nominal test parameters by disc or drum diameter, establishes friction braking share coefficients with c-factor = 1 for full-friction braking, specifies required test input parameters including brake system type and filtering systems, prescribes the Worldwide Harmonized Heavy-Duty Brake Cycle (WHBC) comprising 246 brake events over 5:39 hours across urban, rural, and motorway segments, defines PM and PN measurement methodologies using gravimetrical and particle number counter methods, specifies hardware requirements including brake dynamometer, enclosure dimensions of 1950 mm length × 1000 mm height × 700 mm depth with divider plate, sampling tunnel with 300 mm fixed inner diameter, and brake temperature measurement by embedded thermocouples, and includes results of preliminary interlaboratory study.
Proposal to establish a globally harmonised laboratory methodology for measuring brake particulate matter (PM) and particle number (PN) emissions from heavy-duty vehicles, including trucks and buses, using a Worldwide Harmonized Heavy Duty Vehicles Brake Cycle (WHBC) and brake dynamometer testing. The GTR specifies test system requirements, including brake enclosure design, sampling tunnel specifications, climatic conditioning with cooling air temperature maintained at 23°C±2°C and relative humidity at 50%±5%, cooling airflow at 2500 Nm/h±5%, test preparation procedures, brake bedding with six repetitions of the WHBC followed by emissions measurement during one WHBC cycle, requirements for PM10, PM2.5, TPN10, and SPN10 measurement systems, brake temperature measurement using embedded thermocouples, calibration and validation procedures, and reporting of emission factors. The regulation applies to vehicles of categories M₂, M₃, N₂, N₃ [and O₃, O₄] with friction braking systems.
Proposal to amend UN Regulation No. 179 to include testing of vehicles with limited speed. The document specifies amendments to the laboratory measurement of brake emissions for light-duty vehicles, including provisions for vehicles with a maximum speed lower than the maximum speed of the Base cycle. These vehicles may be part of the same brake corner emissions family as vehicles suitable for the Base cycle, with their emission factor calculated based on the parent family’s reference PM and PN emissions according to equations 7.1, 7.2 and 7.3. At the manufacturer’s request and with approval authority agreement, such limited-speed vehicles may be assigned to a specific family using the adjusted cycle described in Appendix 3 of Annex 4, with the same changes to be applied to UN GTR No. 24.
Proposal to amend and enhance the procedure for laboratory measurement of brake emissions for light-duty vehicles. The document provides comprehensive technical specifications covering scope and application for vehicles of categories M₁ and N₁, detailed abbreviations and symbols for measurement parameters, definitions of vehicle types and brake systems, application and approval procedures, conformity of production requirements with statistical evaluation procedures, and penalty provisions for non-conformity. Testing procedures include three sections: cooling air adjustment, brake bedding, and brake emissions measurement, all executed using the WLTP-Brake cycle comprising ten trips and 303 brake deceleration events. CoP verification shall be performed once every 12 months with samples from each brake corner emission family, evaluated according to decision charts specified in the regulation.
Status report on the EV Fast & Smart Charging cluster’s progress on two main activities: developing the Fast Charge Power Curve (FCPC), a resolution for a test procedure and KPIs, with eight open points requiring validation and verification; and developing a global roadmap on smart and bidirectional charging, which is finalised and to be published as a UN publication in Q1 2027. The cluster’s mandate has been extended for one year to October 2027 to continue validations, resolve open points, and investigate future work including review clauses and a fast charging performance test for heavy-duty vehicles.