RegVault
Free trial

UN R54 Supplement 25 (00 series) · UNECE Regulation No. 54 (ECE R54) — Uniform provisions concerning the approval of pneumatic tyres for commercial vehicles and their trailers.

UN R54 — Supplement 25 to the 00 series of amendments

Supplement 24 → 25

Adopted at the WP.29 187th sessionEntry into force 2023-01-04
CompareRead full text
What changed
  • The markings now give the service description, and one additional service description surrounded by a circle in case paragraph 6.2.5. is applied.
  • Paragraph 6.1.1.2. says how to calculate the section width when the measuring rim width code differs from the one in the Annex 5 tables.
  • For the regroovable symbol or word, paragraph 3.1.10. now reads “on to each sidewall” in place of “moulded into or on to each sidewall”.
Why
  • The proposal aims to clarify the use of an additional load/speed combination for a tyre type.
  • The proposal aims to consolidate the calculation of reference dimensions with UN GTR No. 16, paragraph 3.5.2.3.
  • The proposal extends to the regroovable symbol or word the possibility to be produced with technologies other than moulding.

Q1What changed22 changes

“Load-capacity index” and “Table load-capacity variation with speed” (paras. 2.30. and 2.32.)

In paragraph 2.30., a “load-capacity index” now means “a number which indicates” the load, in place of “one or two numbers which indicate” the load. The words “in single or in single and dual operation” are removed. The sentence on one or two sets of load capacity indices for a type of tyre, depending on paragraph 6.2.5., is also removed. In paragraph 2.32., the load variations do not apply in the case of the additional service description obtained when paragraph 6.2.5. is applied. Before, paragraph 2.32. said “the additional load capacity symbol and speed category”.

"Load-capacity index" means one or two numbers a number which indicate indicates the load the tyre can carry in single or in single and dual operation at the speed corresponding to the associated speed category and when operated in conformity with the requirements governing utilization specified by the manufacturer. A type of tyre can have either one or two sets of load capacity indices depending on whether or not the provisions of paragraph 6.2.5. are applied. The list of these indices and their corresponding loads is given in Annex 4;
The table, in Annex 8, showing as a function of the load-capacity indices and nominal-speed-category symbols the load variations which a tyre can withstand when used at speeds different from that conforming to its nominal-speed-category symbol. The load variations do not apply in the case of the additional load capacity symbol and speed category service description obtained when the provisions of paragraph 6.2.5. are applied;

Service description in the markings (paras. 3.1.5., 3.1.5.1., 3.1.5.2. and 3.1.7.)

Paragraph 3.1.5. now reads “The service description as defined in paragraph 2.35.” in place of “The speed-category symbol (or symbols)”. Paragraph 3.1.5.1. now reads “One additional service description surrounded by a circle in case the provisions of paragraph 6.2.5. are applied”. Before, paragraph 3.1.5.1. read “An indication of the tyre's nominal speed category in the form of the symbol prescribed in paragraph 2.31.2. above”. Paragraph 3.1.5.2. is deleted; it read “An indication of a second speed category in cases where paragraph 6.2.5. below is applied”. Paragraph 3.1.7. now reads “(omitted)”. Before, it read “The load-capacity indices as defined in paragraph 2.30. of this Regulation”.

The speed-category symbol (or symbols);The service description as defined in paragraph 2.35.;
An indication of the tyre's nominal speed category in the form of the symbol prescribed in paragraph 2.31.2. above;One additional service description surrounded by a circle in case the provisions of paragraph 6.2.5. are applied;
2 more changes in this group — open in Compare

Service description in the application for approval (paras. 4.1.5. and 4.1.6.)

Paragraph 4.1.5. now reads “The service description” in place of “The speed category”. Paragraph 4.1.6. now reads “The additional service description in case the provisions of paragraph 6.2.5. are applied” in place of “The load-capacity indexes”.

The speed categoryservice description;
The load-capacity indexes;The additional service description in case the provisions of paragraph 6.2.5. are applied;

Regroovable marking (para. 3.1.10.)

In the case of tyres which can be regrooved, paragraph 3.1.10. now reads “on to each sidewall” in place of “moulded into or on to each sidewall”. This applies to the symbol, at least 20 mm in diameter, or the word “REGROOVABLE”.

In the case of tyres which can be regrooved, the symbol "" at least 20 mm in diameter, or the word "REGROOVABLE", moulded into or on to each sidewall;

Section width of tyre sizes in Annex 5 (para. 6.1.1.2.)

Paragraph 6.1.1.2. now starts with “Notwithstanding paragraph 6.1.1.1.” in place of “However,”. For the tyre designations in the first column of the Annex 5 tables, the section width is deemed to be that given opposite the designation. New text covers the use of a measuring rim whose width code differs from the measuring rim width code listed in the table. In that case, the formula from paragraph 6.1.1.1. is used to calculate the section width. S1 is the section width in millimetres listed in the table. A1 is the measuring rim width code from the table multiplied by 25.4, and the other quantities are as defined in paragraph 6.1.1.1.

However, Notwithstanding paragraph 6.1.1.1., for the types of tyres whose designation is given in the first column of the tables in Annex 5 to this Regulation, the section width shall be deemed to be that given opposite the tyre designation in those tables.
However, if a measuring rim whose width code differs from the measuring rim width code listed in the table is used, the section width is calculated using the formula from paragraph 6.1.1.1., where
3 more changes in this group — open in Compare

References to other paragraphs and the section height formula (paras. 2.13.1., 3.4.1., 6.1.1.3., 6.1.2.3., 6.1.4.3., 6.1.5.1. and Annex 7, para. 3.1.2.)

For tyres identified by the “tyre to rim fitment configuration” symbol “A”, the text now refers to paragraph 2.20.5. Before, paragraphs 2.13.1., 6.1.1.3., 6.1.2.3., 6.1.4.3. and 6.1.5.1. referred to paragraph 3.1.12., and paragraph 3.4.1. referred to paragraph 2.20.1.4. In Annex 7, paragraph 3.1.2. now refers to paragraphs 2.20.6. and 3.1.14. for the additional marking “C” or “LT”, in place of paragraph 3.1.14. The formula in paragraph 6.1.5.1. now reads “H = 0.5 (D − d)” in place of “H = 0.5 (D-d)”.

However, in case of tyres identified by the "tyre to rim fitment configuration" (see paragraph 3.1.122.20.5.) symbol "A", it means the area of the tyre which is seating on the rim;
However, for tyres identified by the "tyre to rim fitment configuration" (see paragraph 2.20.1.4) 2.20.5.) symbol "A", the markings may be placed anywhere on the sidewall of the tyre.
6 more changes in this group — open in Compare
See every change side by side in Compare

Q2Why it changed

Proposed by
Expert from France and experts from the European Tyre and Rim Technical Organization (ETRTO)
Working party
GRBP, 75th session (February 2022)

Reasons

  • The proposal clarifies that one type of tyre can have several additional load/speed combinations as soon as these are tested according to paragraph 6.2.5. However, only one additional service description may be declared and marked on the tyre sidewall, in case paragraph 6.2.5. is applied.

    Sources (2)
    “The purpose of this amendment is to clarify that one type of tyre can have several additional load/speed combinations as soon as these additional combinations are tested according to paragraph 6.2.5.”
    “However, only one additional service description may be declared and marked on the tyre sidewall, in case the provisions of paragraph 6.2.5. are applied.”

  • The aim is to remove an inconsistency in the marking provisions, in line with what was adopted for Supplement 14. The proposal extends to the regroovable symbol or word the possibility to be produced with technologies other than moulding.

    Sources (2)
    “To remove an inconsistency in the marking provisions in this Regulation and in line with what was adopted for Supplement 14 to this Regulation”
    “the possibility to be produced with technologies other than moulding.”

  • The proposal aims to consolidate the calculation of reference dimensions with UN GTR No. 16, paragraph 3.5.2.3. The aim is to allow measuring Annex 5 tyre sizes on rims whose width code differs from the code listed in the Annex 5 tables.

    Sources (2)
    “It is proposed to consolidate the calculation of reference dimensions with that provided in United Nations Global Technical Regulation (UN GTR) No. 16, paragraph 3.5.2.3.”
    “to allow measuring tyres with size designations listed in Annex 5 on rims whose width code differs from the measuring rim width code listed in the tables of Annex 5.”

  • Proposer's reason (informal document GRBP-75-31-Rev.2)

    The purpose is to avoid placing requirements in the Definitions section. The purpose is also to facilitate the text by making use of the definition of “service description” that was introduced by Supplement 24.

    Submitted by Expert from ETRTO. Working party adoption: ECE/TRANS/WP.29/GRBP/73, para. 18.

    Source
    “The purpose of this proposal is to avoid placing requirements in the Definitions section and to facilitate the text by making use of the definition of "service description" that was introduced by Supplement 24.”

  • Proposer's reason (informal document GRBP-75-31-Rev.2)

    It is also proposed to correct certain references to paragraphs that were omitted or changed by Supplement 24.

    Submitted by Expert from ETRTO. Working party adoption: ECE/TRANS/WP.29/GRBP/73, para. 18.

    Source
    “Furthermore, it is proposed to correct certain references to paragraphs that were omitted or changed by Supplement 24.”

Document trail

  1. 2021-06ProposalECE/TRANS/WP.29/GRBP/2021/13Proposal by the expert from France
  2. 2021-11ProposalECE/TRANS/WP.29/GRBP/2022/6Proposal by the experts from ETRTO
  3. —Amended in sessionGRBP-75-31-Rev.2Changes to both proposals, submitted by the expert from ETRTO
  4. —Working party adoptsECE/TRANS/WP.29/GRBP/73Session report, para. 18
  5. 2022-04Sent to WP.29ECE/TRANS/WP.29/2022/85Text that GRBP sent to WP.29 and AC.1
  6. 2022-06WP.29 adoptsECE/TRANS/WP.29/1166Adopted at the 187th session (session report, para. 182)
  7. 2023-01-04In forceC.N.479.2022.TREATIES-XI.B.16.54UN depositary notification

Q3Who is affected

Vehicle manufacturer

  • No direct action for this role.

Component supplier

  • No direct action for this role.

Technical service / Approval authority

  • Calculate section width of Annex 5 tyre sizes on a measuring rim of another width code by the 6.1.1.1. formula.

See every change side by side

RegVault customers compare every version of UN regulations, read the consolidated text and download the PDF.

Start free trialSign in

ⓘ This report gives advice only. It is not legal or type-approval advice.

More UN R54 change reports

All UN R54 change reports