UN R172 Supplement 1 (00 series) · UNECE Regulation No. 172 (ECE R172) — Uniform provisions concerning the approval of retreaded tyres with regard to their snow performance and/or classification as traction tyre.
UN R172 — Supplement 1 to the 00 series of amendments
Base text → Supplement 1
- What changed
- As from 1 September 2030, Contracting Parties must not grant type approvals based on “snow performance tests as described in Annex 7 to UN Regulation No. 117” using SRTT19.5 or SRTT22.5 as reference tyre. The table in paragraph 6.1. now also lists SRTT19.5 siped and SRTT22.5 siped.
- Paragraph 6.4. now sets a maximum speed category for class C2 and class C3 special use tyres to be classified as ‘professional off-road tyre’. Before, the paragraph also set a tread depth and a void-to-fill ratio, and it had an item for C1 tyres.
- Paragraph 5.5. now applies to a retreaded tyre “approved pursuant to this Regulation” and produced in “a retreading production unit which conforms to an approval under UN Regulations Nos. 108 or 109 that has the retreaded tyre as part of the range of tyres approved in and by the country which has granted approval under this Regulation”.
- Why
- The new reference tyres C3 SRTTs 19.5 and 22.5 siped were introduced by the 04 series of amendments to UN Regulation No. 117.
- With respect to the transitional provisions in UN Regulation No. 117 for the same item, two additional years are considered. The aim is to allow the type approval of retreaded tyres by using the UN Regulation No. 117 certificate of new tyres “having a tread pattern with the same major features”.
- An editorial revision was proposed to simplify the wording of the requirements for professional off-road tyres.
Q1What changed23 changes
Transitional provisions for SRTT19.5 and SRTT22.5 (paras. 12., 12.1., 12.2. and 12.3.)
New paragraph 12. gives transitional provisions. Paragraph 12.1. is about “snow performance tests as described in Annex 7 to UN Regulation No. 117” using SRTT19.5 or SRTT22.5 as reference tyre. As from 1 September 2030, Contracting Parties must not grant type approvals based on these tests. Under paragraph 12.2., as from 1 September 2030, Contracting Parties are not obliged to accept such type approvals first issued after 31 August 2030. Paragraph 12.3. covers existing type approvals of class C3 tyres first granted before 1 September 2030 and based on these tests. Notwithstanding paragraph 12.1, Contracting Parties must continue to grant extensions to these approvals.
Reference tyres SRTT19.5 siped and SRTT22.5 siped (paras. 6.1. and 12.3.)
In the table of paragraph 6.1., the cell “Ref.s = SRTT19.5, SRTT22.5” now reads “Ref.s = SRTT19.5, SRTT22.5, SRTT19.5 siped, SRTT22.5 siped”. The cell “Ref.s =, SRTT16” now reads “Ref.s = SRTT16”. Under paragraph 12.3., if an extension after 1 September 2030 needs a new test on “a different representative tyre size”, SRTT19.5 siped and SRTT22.5 siped must be used.
Professional off-road tyres (para. 6.4.)
Paragraph 6.4. now says that, to be classified as a ‘professional off-road tyre’, “a special use tyre shall fulfil the following additional requirement”. Before, it said that “a tyre shall have all of the following characteristics”. Item (a) now sets, for class C2 tyres, a maximum speed category “less than or equal to 160 km/h (speed category symbol Q)”. Item (b) now sets, for class C3 tyres, a maximum speed category “less than or equal to 110 km/h (speed category symbol K)”. Before, items (a), (b) and (c) gave a tread depth, a void-to-fill ratio and a speed category for C1, C2 and C3 tyres. These items are deleted.
Symbol of paragraph 5.4.1. and approvals under UN Regulations Nos. 108 or 109 (para. 5.5.)
Paragraph 5.5. tells when it is not needed to repeat the symbol prescribed in paragraph 5.4.1. The words “approved pursuant to this Regulation” are added after “If the retreaded tyre”. After “108 or 109”, the words “that has the retreaded tyre as part of the range of tyres approved” are added, and “in the country” now reads “in and by the country”. The text now says “UN Regulations Nos. 108 or 109” instead of “the Regulation 108 or 109”.
“RETREADED” in Annex 1, Appendices 1 and 2
In Annex 1, Appendix 1, paragraph 1. now reads “TYRES TO BE RETREADED” instead of “TYRES TO BE RETREATED”. In Annex 1, Appendix 2, paragraph 1. now reads “RETREADED TYRES” instead of “RETREATED TYRES”.
Q2Why it changed
- Proposed by
- Experts from the European Tyre and Rim Technical Organization
- Working party
- GRBP, 81st session (February 2025)
Reasons
The 04 series of amendments to UN Regulation No. 117 introduced the new reference tyres C3 SRTTs 19.5 and 22.5 siped, with pertinent transitional provisions. They complement the current reference tyres C3 SRTTs 19.5 and 22.5.
Source
“The current reference tyres C3 SRTTs 19.5 and 22.5 have been complemented by the new reference tyres C3 SRTTs 19.5 and 22.5 siped introduced by the 04 series of amendments to UN Regulation No. 117 with pertinent transitional provisions.”
With respect to the transitional provisions in UN Regulation No. 117 for the same item, two additional years are considered. The aim is to allow the type approval of retreaded tyres by using the UN Regulation No. 117 certificate of new tyres “having a tread pattern with the same major features”.
Source
“two additional years are considered in order to allow the type approval of retreaded tyres by using the UN Regulation No. 117 certificate of new tyres having a tread pattern with the same major features.”
An editorial revision was proposed to simplify the wording of the requirements for professional off-road tyres.
Source
“Editorial revision is proposed to simplify the wording of the requirements for professional off-road tyres.”
The full text of the UN Regulation was also made subject of editorial corrections where needed.
Source
“Additionally, the full text of the UN Regulation has been made subject of editorial corrections where needed.”
Proposer's reason (informal document GRBP-81-27-Rev.2)
The wording of paragraph 5.5. was reviewed to clarify when there is no need to repeat the symbol prescribed in paragraph 5.4.1.
Submitted by Experts of ETRTO. Working party adoption: ECE/TRANS/WP.29/GRBP/79, para. 22.
Source
“The wording of paragraph 5.5. has been reviewed to clarify when there is no need to repeat the symbol prescribed in paragraph 5.4.1.”
Document trail
- 2024-12ProposalECE/TRANS/WP.29/GRBP/2025/17Proposal by the experts from ETRTO
- —RevisedGRBP-81-27-Rev.2Proposal to replace GRBP/2025/17, transmitted by the experts of ETRTO
- —Working party adoptsECE/TRANS/WP.29/GRBP/79Session report, para. 22
- 2025-04Sent to WP.29ECE/TRANS/WP.29/2025/78Text that GRBP sent to WP.29 and AC.1
- —Amended in sessionECE/TRANS/WP.29/1186WP.29 session report, para. 72: editorial correction to paragraph 12.3
- 2025-06WP.29 adoptsECE/TRANS/WP.29/1186Adopted at the 196th session (session report, para. 111)
- 2026-01-11In forceC.N.49.2026.TREATIES-XI.B.16.172UN depositary notification
Q3Who is affected
Vehicle manufacturer
- No direct action for this role.
Component supplier
- For type approvals from 1 September 2030, plan snow performance tests without SRTT19.5 or SRTT22.5 as reference tyre.
- For class C3 tyres, if an extension after 1 September 2030 needs a new test on “a different representative tyre size”, use “SRTT19.5 siped and SRTT22.5 siped”.
Technical service / Approval authority
- Be ready to use SRTT19.5 siped and SRTT22.5 siped as reference tyres in snow performance tests.
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ⓘ This report gives advice only. It is not legal or type-approval advice.