GRBP/2025/10
UN R54: Proposal for Supplement 28

Proposal to

  1. 1. Add a generic reference to the Consolidated Resolution on the Construction of Vehicles (R.E.3) in footnote 1
  2. Make editorial corrections to the type of tyre and additional service description definitions
  3. Clarify the definition of nominal rim diameter (in line with the proposal for amending UN R30)
  4. Amend the definition of principal grooves (in line with the proposal for amending UN R30
  5. Introduce a definition for tread depth (used in the requirements for special use and professional off-road tyres)
  6. Introduce definition for free rolling tyre and front axle, and related revision of markings (ref. GRBP-80-03 and GRBP-80-26)
  7. Clarify the Dmax requirement for snow tyres
  8. Simplify rhz wording of the requirements for professional off-road tyres
  9. Add an indication for whether a special use tyre is a professional off-road tyre to the communication form (in line with UN R30).

UNECE server
Excerpts from session reports
GRBP | Session 81 | 18-21 Feb 2025

12. The expert from ETRTO presented background information on a set of proposals clarifying definitions and making editorial changes in several UN Regulations on tyres (GRBP-81-13-Rev.1). For UN Regulation No. 30, ETRTO tabled draft amendments in ECE/TRANS/WP.29/GRBP/2025/9. GRBP adopted this proposal, as amended by GRBP-81-05-Rev.1 and subject to correcting the new paragraph number to 2.25.3.4.1. and requested the secretariat to submit it for consideration and vote at the June 2025 sessions of WP.29 and AC.1 as draft Supplement 27 to the 02 series of amendments to UN Regulation No. 30.

13. The expert from ETRTO introduced draft amendments to clarify several definitions and to make editorial changes (ECE/TRANS/WP.29/GRBP/2025/10). GRBP adopted these proposals, as amended by GRBP-81-06-Rev.1, and requested the secretariat to submit them for consideration and vote at the June 2025 sessions of WP.29 and AC.1 as draft Supplement 28 to UN Regulation No. 54.

WP.29 | Session 196 | 23-27 Jun 2025

71. The Chair of GRBP presented draft amendments under agenda item 4.8.1. The World Forum recommended their submission to AC.1 for voting.

72. WP.29 considered draft amendments under agenda items 4.8.2 to 4.8.13 and recommended their submission to AC.1 for voting, subject to the following editorial corrections: ECE/TRANS/WP.29/2025/68, ECE/TRANS/WP.29/2025/71, ECE/TRANS/WP.29/2025/72, paragraph 6.1.1.1., amend to read: “6.1.1.1. The section width S of a tyre fitted on the measuring rim shall be calculated by the following formula: , and rounded to the nearest millimetre, Where: S1 is the nominal section width in millimetres, as shown on the sidewall of the tyre in the tyre designation as prescribed; …” ECE/TRANS/WP.29/2025/72, Annex 5, Table 7, first column, rows MU90-15, MV90-15, MU85-16, MV85-15, delete “M/C”. ECE/TRANS/WP.29/2025/73, paragraph 2.22.1., the first sentence, amend to read: “When the nominal rim diameter (“d” symbol) is expressed by code, the values of the “d” symbol are as follows:…”. ECE/TRANS/WP.29/2025/76, paragraph 6.8., first sentence, delete “all of”. ECE/TRANS/WP.29/2025/77, paragraph 5.2.3.2.2., replace “… the Snow Grip Symbol for Studded Tyres1 as described in UN Regulation No.” with “… the Snow Grip Symbol for Studded Tyres1 as described in UN Regulation No. 164)”. Paragraph 5.2.5.2., first line, delete “a”. ECE/TRANS/WP.29/2025/78, paragraph 12.3, replace “… based on snow performance test described in Annex 7 to this Regulation…” with “… based on snow performance test described in Annex 7 to UN Regulation No. 117…”.