Introduce the definition of “dual fitment”

Existing transitional provisions do not address the issue of retreaded tyres produced in accordance with the applicable requirements before 1 September 2028. Thus, a significant quantity of retreaded tyres will stay stocked within the different stages of the distribution channels.

Proposal to clarify that an extended mobility tyre shall not be retreaded without being marked with the EMT symbol to avoid the mix up on the same axle with a tyre of radial structure not featuring extended mobility capabilities

Proposal introduces the definition of “dual fitment” which is missing in the current text and improves the readability of the text by using only the wording “dual fitment”, mentioning the alternative wording “twin fitment” in a note.
Solves problem of type approving LT tyres with load-capacity index greater than or equal to 122 and suitable for dual fitment.

Proposal to improve the readability of the text by using only the wording “run flat tyre”, mentioning the alternative wording “self supporting tyre” in a note and restricts the use of ZR and ZRF marking to the tyres suitable for speeds greater than 300 km/h.

Road legal race tyres are currently defined in the new UN R186 on abrasion but fall out of its scope. Considering that the new UN R186 on abrasion applies only to tyres that conform to UN Regulation No. 117., it is proposed to replicate therein the definition, the marking and the requirements of road legal race tyres by adding the new paragraphs 2.21., 4.5. and 6.9.

Proposal replaces the GRBP2026/26

Proposal for a Guideline regarding the Interpretation of Paragraph 6.2.3. ASEP in the 03 series of amendments to UN Regulation No. 51, updating Informal Document GRB-68-03 and based on GRB/2005/5 and GRB/2010/9. Part A addresses internal combustion and hybrid vehicles when the combustion engine is operating, defining typical on-road driving as vehicle speeds between 15 km/h and 100 km/h, accelerations not exceeding 2 m/s² and vehicle performance not exceeding 35 m/s², and engine speeds of at least 1.5 times idle speed and not exceeding the maximum outlined in Annex 7. Significant deviation means sound level exceeding reference values by at least 6 dB(A). Type approval test results derive from Annex 3 or Annex 7 values, with reference values established using regression curves or calculation principles. Part B addresses electric and hybrid vehicles propelled electrically only, extending guidance to electrified vehicles and Enhanced Exterior Sound introduced by Supplement 11. Typical on-road driving for electric vehicles includes vehicle speeds greater than 0 km/h and up to 100 km/h and standstill covered by UN-R 138. Significant deviation for electric vehicles is at least 3–6 dB(A).

Progress Report (February 2026 – September 2026)
Conclusion of work on UN Regulation on tyre abrasion for C1 tyres, launch of C2 work, outlook for C3 work

Rationale for Figure Part B.5 of GRBP-84-36-Rev.1

Proposal to amend para. 6.2.1.1. to permit testing of vehicle sound either indoors or outdoors with equivalent results, add new Annex 11 specifying indoor testing provisions, amend Annex 1 to insert para. 8.5. and 8.5.1. requiring documentation of test method selected, amend Annex 3 para. 1. to specify sound level meter requirements for indoor testing per IEC 651 and IEC 61672-3, amend Annex 3 para. 1.1.1. to provide calibration procedures for indoor testing per IEC 942:1988, amend Annex 3 para. 1.3. to exempt wind speed monitoring for indoor facilities, amend Annex 3 para. 2.1. and add para. 2.1.4. to specify outdoor and indoor test site requirements per ISO 362-3:2022 and ISO 26101, add para. 2.1.5. specifying indoor ambient conditions, add para. 2.2.7. addressing test mass for indoor dynamometer testing, amend Annex 3 para. 3. to specify outdoor and indoor test procedures per ISO 362-3:2022 Variant A, amend Annex 3 para. 3.1.1. to clarify outdoor testing microphone placement, add para. 3.1.1.4. defining virtual lines and simulated vehicle speeds for indoor testing, and renumber former paras. 3.1.1.4. and 3.1.1.5. as 3.1.1.5. and 3.1.1.6.

Proposal to amend UN Regulation No. 142 to clarify that a maximum speed warning label specifying the lowest value of the maximum speed capability of fitted snow tyres displayed inside the vehicle in a prominent position readily and permanently visible to the driver can be via a permanent physical label or an electronic display, and in case of an electronic display the warning can be shown permanently or when the respective speed limit is approached, reached or exceeded, and to provide that the speed warning label shall not be required for vehicles of categories X and Y equipped with an ADS.

Proposal to improve the readability of the text by using only the wording “run flat tyre”, mentioning the alternative wording “ self supporting tyre” in a note.