The agenda includes adoption of the provisional agenda and minutes from the thirty-eighth session; proposals for amendments to R155 concerning multistage vehicles, separate technical units and component approval, and remote operation for automated driving systems; review of cyber and software requirements in the ADS Regulation; application of RXSWIN to R156; administrative provisions in R155 and R156 regarding Type Approval Authority for CSMS/SUMS and issuing approvals for out-of-scope vehicle types; and preparation of GRVA 26.

IWG RD-ASEP created a mandatory test assessing compliance with paragraph 6.2.3 of Regulation 51.03 (later 51.04) to assure vehicle noise emission at speed, load, or acceleration conditions other than Annex 3 condition is linked to vehicle physics, with no noise emission test detection or defeat device schemes. R51.04 draft incorporates R51.03 Supplements up to Supplement 11, revises manipulation and defeat device provisions, establishes mandatory random RD-ASEP testing for approval with expanded vehicle speed range of 1-100 km/h and vehicle performance criteria, and includes expectation model technical basis in Annex 7.

The agenda includes adoption of meeting minutes from the 5th EDO Meeting and two intermediate sessions, documents for WP.29’s 200th session requesting authorization to amend UN GTR No. 1 and 14, transformation to IWG with Terms of Reference and Rules of Procedure, amendments to UN Regulation No. 11 and No. 21, discussion of open items, and preparation of working documents for GRSP’s 80th session.

Draft agenda of the 76th session of the Informal Working Group WGWT scheduled for August 28th, 2026 on-line. The agenda includes welcome and opening remarks, adoption of the agenda, adoption of the minutes of the 75th session of 16 June 2026, review of work plan 2025-2026 for C1 tyres, review of IWG WGWT status report for GRBP 84th session of September 2026, and next meetings.

UN GTR No. 25 on In-vehicle Battery Durability for Electrified Heavy Duty Vehicles provides harmonised methods to determine battery durability performance of HD-PEVs and HD-OVC-HEVs of categories M₁–M₃ and N₁–N₃ exceeding 3,855 kg MPLM. The regulation requires manufacturers to install State of Certified Energy (SOCE) monitors throughout vehicle lifetime. In-use verification consists of Part A verification of monitor accuracy through measured UBE testing using Methods 1a, 1b, Method 2 (bidirectional power supply), or an alternative HDV chassis dynamometer method, with statistical pass/fail criteria. Part B verification assesses battery durability against optional Minimum Performance Requirements (MPRs) through remote SOCE data collection from sample vehicles. Part C verification, reserved for future amendment, will address reported virtual distance accuracy for V2X, PTO and non-traction purpose applications. Optional Annex 4 specifies MPRs by vehicle category and mass, ranging from 45–70% SOCE retention across specified timeframes and distances. The GTR entered into force with Phase 1 covering core durability assessment and data collection to support future refinement of MPR thresholds based on in-service field data relating to HDVs, referencing WP.29-170-31 and GRPE/2026/3.

UN GTR No. 22 on In-vehicle Battery Durability for Electrified Light Duty Vehicles establishes harmonized requirements for monitoring and verifying minimum battery durability performance of pure electric vehicles and off-vehicle charging hybrid electric vehicles of categories M₁ and M₂. Manufacturers must install State-of-Certified Energy (SOCE) and State-of-Certified Range (SOCR) monitors for the vehicle lifetime. Battery energy-based minimum performance requirements specify that vehicles of categories 1-1 and 1-2 must retain 80 per cent SOCE for 5 years or 100,000 km and 70 per cent for 8 years or 160,000 km; category 2 vehicles must retain 75 per cent and 65 per cent respectively. In-use verification comprises Part A verification of monitor accuracy using statistical methods, Part B verification of battery durability through remote data collection, and Part C verification of reported virtual distance. Manufacturers may declare higher performance requirements. Virtual distance may be reported for vehicles with Vehicle-to-Grid functionality or category 2 vehicles used for non-traction purposes.

Proposal to amend UN GTR No. 21 on system power determination:

• Establish a globally harmonized test procedure comparable to traditional engine power ratings for conventional vehicles,
• specify TP1 based on measured electrical power and estimated internal combustion engine power with electrical conversion efficiency factors,
• specify TP2 based on measured torque and speed at axle shafts or wheel hubs with mechanical conversion efficiency factors,
• require manufacturers to provide verifiable K conversion factors,
• remove dynamometer roller measurement options for TP2 in favor of torque and speed sensors or hub dynamometers,
• mandate fuel flow rate measurement for TP1,
• introduce the reference point concept to ensure comparable results across powertrain architectures,
• require five test repetitions with averaging of the last four,
• add applicability guidelines limiting TP1 or TP2 to specific architectures based on power flow characteristics,
• establish approval criteria for system bench facilities as alternatives to chassis or hub dynamometers in a new Annex 3.