Proposal to amend UN Regulation No. 172 based on GRBP/2026/10 as amended by GRBP-83-15-Rev.1. Amendments include revised definition of supplier of tread in paragraph 2.2.; modification of paragraph 6.2. to require tyres to meet conditions in paragraph 6.2.1. or 6.2.2.; insertion of new paragraphs 6.2.2., 6.2.2.1., 6.2.2.2., and 6.2.2.3. establishing calculation methods for deformation potential and number of traction elements based on tyre class and nominal rim diameter; insertion of new paragraph 6.4.(a) for class C₁ tyres; renumbering of former paragraphs 6.

Proposal to amend paragraph 2.2. to clarify the definition of “Supplier of the tread used for retreading process”; insert new subparagraph (a) in paragraph 6.4. establishing requirements for class C1 tyres; renumber former subparagraphs (a) and (b) as (b) and ©; replace “Appendix 1” with “Schedule 1” in paragraph 8.; amend paragraph 12.1. concerning type approvals as from 1 September 2030; amend paragraph 12.3. regarding acceptance of existing type approvals of class C3 tyres; and amend Annex 1 regarding communication of type approval for retreaded tyres.