Consolidated version integrating GRBP/2022/13, GRBP/2022/16 and GRBP-76-09 as adopted during the 76th GRBP session and including corrections and clarifications per GRBP/2023/12.

Proposal from the Informal Working Group on Measurement Uncertainties (IWG MU) to amend UN R51 with tables showing the measurement uncertainties when performing type-approval, COP, or field testing (e.g. market surveillance).

The measurement uncertainties developed in this Appendix are based the IWG MU work and its Document for Reference which describes a general approach to estimate measurement uncertainties (GRBP/2022/9/Rev.2). The impact of the quantities on the expanded uncertainty has been evaluated separately for run-to-run, day-to-day, vehicle-to-vehicle and site-to-site variations. Some of the different impacts are based on calculations from tolerances in Annex 3, while others are based on experiences.

Outcomes from discussions in the GRBP Special Interest Group on AV Regulatory Screening.

Report on discussions concerning the feasibility of a new UN Regulation on uniform provisions for the approval of pre-cured tread materials used for producing retreaded tyres or the approval of retreaded tyres produced by using mould cure process with regard to their snow performance.

Proposal from the Noise Measurement Uncertainties informal group for amendments to Annex 3.

Proposal to replace GRBP/2023/11 with a revised proposal to address the following:

1. “Special use” tyres with nominal rim diameters larger than those listed in the present table (rim diameters up to 42, section widths up to 750 mm and overall diameters over 2 meters) and with speed symbols F and above have been announced in the European market as original equipment of N3G “special purpose vehicles” (i.e., special high speed self-propelled vehicles for agricultural and forestry use, like wood choppers).

2. Existing multi-purpose tyres (MPT) (classified as “special use tyres” as per paragraphs 2.5.3. and 3.1.13.), already type approved since years, have a tread pattern with lugs or cleats in addition to those with blocks, as evidenced by the attached slide showing some examples. It is proposed to amend paragraph 6.3.1. by clarifying that lugs and cleats are possible shapes of the mentioned blocks.

3. Testing tyres with very large overall diameters, sometimes over 2 m, on a test drum with a diameter of 1.70 m ± 1 % would be unpracticable. For practical reasons most of those tyres are regularly tested on drums with a diameter of 3 m or even larger. The proposal carries equivalence provisions from UN R106 to justify the equivalence of the test method as required by Annex 7 in point 4 “Equivalent test methods" and clarifies based on UN R117 the formula already used indirectly.

4. Some commercial vehicles are often used in the market at a reduced speed of 70 km/h with a load-capacity of the tyres increased as per load/speed combination defined in the table of Annex 8. The proposal would allow use of the speed category symbol E (but restrict it to “additional service description”) to provide this information.

5. Considering that 32 km/h is already a floor value for the test-drum speed for diagonal tyres, ETRTO proposes not to apply to E speed category symbol tyres the linear decrease of the test-drum speed in function of the decrease of the speed category symbol by keeping, for safety reasons, the same test-drum speed as for F speed category symbol tyres, i.e., 32 km/h).

6. In the case of additional service descriptions mentioned in paragraph 6.2.5.1., it is proposed not to perform the additional load/speed test because the load-capacity approximates with a negligeable difference the reduction or the increase in percentage of the nominal load/speed combination applicable to the nominal speed category symbol (see Annex 8). An example of the actual differences (in percentage and in absolute value) is provided.

7. Type approval applications for radial tyres with load capacity index greater or equal to 122 and without the additional marking “LT”, or “C” have been done in the past for the speed category symbol N for which the load/speed endurance test procedure is not described in Annex 7, Appendix 1. To type approve such tyres the test speed was separately defined by the different involved Type Approval Authorities. In order to harmonize the test procedure to be used for the type approval of such tyres, it is proposed to amend the Annex 7, Appendix 1 by introducing testing conditions in line with the rule applied for defining the test speed of radial tyres with load capacity index greater or equal to 122 (i.e. starting from 32 km/h set for F speed category symbol, the test speed is increased by 8 km/h respect to the one set for the previous speed category symbol).

8. The definition of “snow tyre” is amended to clarify that “snow tyres” are not only suitable for the use in snow conditions but also on mud and by replacing the term “maintain vehicle motion” (i.e. keeping the vehicle speed and direction of movement constant) by a more general concept of “controlling vehicle motion” (i.e. also being able to change the vehicle speed and direction of movement as intended).

9. It is proposed to explicitly allow other technical measurement solutions of the tyre overall width by removing the words “by caliper” which fix a technical limitation. The removal of this technical limitation would be advisable following the principle of not stopping the technical innovations.

Request to allocate time on the agenda of the 78th session for consideration of performance requirements for tyres used on heavy-duty pickup trucks designed for professional tasks on rough terrains.

Proposal to supersede GRBP/2023/10 with a more flexible approach appropriate for covering the operations of small retreaders.

Editorial amendment to align the definition of “special tyre” with the proposal for the snow tyre definition in paragraph 2.33.

Proposal to clarify the details of the data-handling during the monitoring phase required in paragraph 5.1.1.

Proposal from the Measurement Uncertainties informal group to introduce measures to reduce variability in noise measurements.

Proposal to specify explicitly that the maximum overall width of tyres identified by the “tyre to rim fitment configuration” symbol “A” includes a 4 per cent tolerance.

Proposal to provide industry guidelines on anti-tampering provisions for Non-Original Replacement Exhaust Silencing Systems (NORESS) in UN Regulation No. 92.

Proposal to allow using the state-of-the-art test track from the latest standard ISO 10844:2021.

Proposal to allow using the state-of-the-art test track from the latest standard ISO 10844:202

Proposal to allow using the state-of-the-art test track from the latest standard ISO 10844:2021.

Proposals:

• Para. 2.2.3.: Information related to construction materials is clarified.
• Para. 2.2.4.: Deleted, since its content is covered by paragraph 2.2.8. in the proposed wording.
• Para. 2.2.8.: The notion of the wheel geometric shape is clarified.
• Para. 2.9.: The notion of defects caused by the production process is clarified. Only in the Russian language it is clarified that the crack propagation is actually a length and a depth of the crack. The proposed text makes it possible to distinguish between a crack that occurred during testing and a scratch, which may be an acceptable manufacturing defect.
• Para. 3.1.2.13.: The technical description of the wheel is supplemented with information describing the product quality control in the production process.
• Para. 5.1.6. and Annex 3: The application of optional marking is aimed at providing the consumers with information on the quality control of the manufactured wheel, as well as facilitating the selection of wheels with the required characteristics by consumers in case of providing with incomplete information on suitable vehicle types in accordance with paragraph 1.2. of Annex 10.
• Annex 4, para. (а): The language of the provision is clarified.
• Annex 4, paras. (b) and (d): Deleted, since the existing experience of testing confirms that the mechanical properties of the raw materials are not comparable with the mechanical properties of finished products (wheels). In this regard, there is no need to test the raw materials.
• Annex 4, para. (с): The list of critical zones on wheels where to take the material to check its characteristics is clarified. These critical zones shall be specified by the manufacturer in the application documentation, and they can also be specified by the technical service. A description of the characteristics of the material taken from paragraph (b) is provided, since this paragraph is deleted. Only in the Russian language the terms concerning the measured values have been changed.
• Annex 4, para. (e): It is specified that the analysis of metallurgical defects is carried out in the most loaded spots of the wheels. These spots shall be specified by the manufacturer in the application documentation, and they can also be specified by the technical service. The analysis shall be carried out in comparison with the permissible defects specified by the manufacturer.
• Annex 6: A recommendation is added to identify cracks occurred as a result of the test by using penetrating paints.
• Annexes 7 and 8: The pressure drop in the tyre as a consequence of testing the wheel assembly with the tyre may not be due to damage to the wheel, but to damage to the tyre. To eliminate uncertainty in the interpretation of the test results, it is necessary to determine the cause of the tyre pressure drop. If the pressure drop in the tyre was caused by its damage, then it is necessary to carry out the tests again, using a new tyre.

Proposal for a reference document concerning a general approach for how to handle measurement uncertainties under UN Regulations within the purview of GRBP.

Submitted by the Chair of informal group on Measurement Uncertainties.

Proposal from the Noise Measurement Uncertainties informal group to update provisions related to temperature sensitivity.

Consolidated text prepared by the QRTV task force (for information).

Status report of the task force on the 02 series of UN R138.

This proposal concerns to amendments to Annex 7. The proposed changes regarding sound enhancement systems are based on the 03 series of amendment up to Supplement 9. In addition, some clarifications concerning power definition and temperature correction have been included based on experiences with the last changes of this regulation.

Proposal from the informal group on Measurement Uncertainties to introduce provisions on exterior noise measurements when performing type-approval, COP or, field testing (e.g., market surveillance).

Proposal from the informal group on Measurement Uncertainties, superseding the proposal in document GRBP/2023/19.

Proposal to update the terms of reference for the Informal Working Group on Real Driving-Additional Sound Emission Provisions (RD-ASEP) covering vehicles of categories M₁, N₁, and L₃, with primary objectives to develop amendments from monitoring data, modify current regulations to mandate revised RD-ASEP, update Annex 9, delete Annex 7, and develop consistency between UN R51 and UN R138, chaired by Germany with OICA as Secretary for M/N categories and IMMA for L category, with working documents for motorcycles by January/February 2025, for M₁ and N₁ vehicles by end of 2025 for GRBP discussion in January/February 2026.

Information concerning discussions on the proposals to extend the scope to ‘E’ speed symbol.

Comments concerning:

• AVAS Pause Switch
• AVAS Sound Pressure Levels
• Maximum AVAS Sound Pressure Level
• AVAS Sound when vehicle stationary

Proposal to transition test facilities from ISO 10844:2014 to ISO 10844:2021 by January 2029.

Proposal from a small group effort for uniform provisions concerning the approval of pre-cured tread materials which are used for producing retreaded tyres or the approval of retreaded tyres produced by using mould cure process with regard to their snow performance.

Small group proposal to split retreaded tyre requirements into a new UN Regulation.

Small group (France, Netherlands, ETRTO, BIPAVER) proposal to restructure retreaded tyre requirements and regulations.

Proposal to amend rolling resistance provisions with regard to heavy-duty-use light trucks.

Proposal to reduce noise measurement variability, completing the amendment proposal adopted at the seventy-eighth session of the Working Party on Noise and Tyres (informal document GRBP-78-05 replacing ECE/TRANS/WP.29/GRBP/2023/19).

Proposal to introduce a new temperature correction formula for the rolling sound emissions of tyres of classes C1 and C2, to remove the content of the now obsolete Annex 4 as well as all its references, to update references to standards, and to make editorial improvements for clarity and consistency across tyre regulations.

Proposal to improve the reproducibility of the snow grip test method by replacing the current reference tyres C3 SRTTs 19.5 and 22.5 with the new reference tyres C3 SRTTs 19.5 and 22.5 siped.

Proposal to complete the amendment proposal adopted at the 78th GRBP session (informal document GRBP-78-05 replacing ECE/TRANS/WP.29/GRBP/2023/19).

Proposal to allow the use of LT-marked tyres under certain conditions and weight limits with a rolling resistance greater than the current limits.

Proposal to clarify the text:

• Term “construction materials”
• interpretation of paras. 2.2.4. and 2.2.8.
• supplement technical description of the wheel with information describing production quality control
• option for additional consumer-oriented marking
• clarify Annex 4 and exclude aluminum-alloy and magnesium-alloy wheels under test (b)
• clarify Annex 6 with regard to possible defects caused by the production process and not affecting the appearance of cracks during testing
• recommend under Annex 6 to identify cracks occurred as a result of the test by using penetrating paints
• clarify Annexes 7 and 8 with regard to air leakage.

Proposal to align Annex 9 with Annex 1 (paragraphs 5., 6. and 7.) and to enable type approval authorities to make the connection with the relevant reports.

Proposal to improve the reproducibility of the snow grip test method by replacing the current reference tyres C3 SRTTs 19.5 and 22.5 with the new reference tyres C3 SRTTs 19.5 and 22.5 siped.

Proposal from the ad hoc working group on retreaded tyres to move provisions for snow grip performance of retreaded tyres and their classification as traction tyres from UN R108 into a new UN Regulation on type approval of retreaded tyres of classes C1, C2 and C3 with respect to their snow grip performance and/or classification as traction tyre.

Proposal from Task Force on Tyre Abrasion (TFTA) to introduce test methods to measure tyre abrasion.

Proposal from the ad hoc working group on retreaded tyres to move provisions for snow grip performance of retreaded tyres and their classification as traction tyres from UN R108 and R109 into a new UN Regulation on type approval of retreaded tyres of classes C1, C2 and C3 with respect to their snow grip performance and/or classification as traction tyre.

Proposal for editorial corrections.

Proposal from the Measurement Uncertainties informal group for a Document for Reference providing a general approach on how to handle measurement uncertainties in UN Regulations (initially addressing UN Regulations Nos. 51 and 117).

Proposal to specify the working principles of an Acoustic Vehicle Alerting System (AVAS) and to reduce measurement uncertainties during the measurement of the one third octave bands.

Proposal from the ad hoc working group on retreaded tyres to move provisions for snow grip performance of retreaded tyres and their classification as traction tyres from R109 into a new UN Regulation on type approval of retreaded tyres of classes C1, C2 and C3 with respect to their snow grip performance and/or classification as traction tyre.

Proposal for editorial improvements and updates to ISO and ASTM standards references and to align with Supplement 2 to the 04 series of amendments, including a new temperature correction formula for the rolling sound emissions of tyres of classes C1 and C2 and to remove the content of the now obsolete Annex 4 as well as all its references.