UN R117 — 03 series of amendments

Paragraph 1.1. now also covers class C1 tyres in worn state for adhesion performance on wet surfaces. Tyres of classes C1, C2 and C3 are covered in new state. In paragraph 1.2., “wet adhesion” becomes “adhesion of tyres in new state on wet surfaces and/or adhesion of tyres in worn state on wet surfaces”. New paragraphs 2.19.17. and 2.19.18. define “Tyre in worn state” and “Tyre in new state” as the tyre in a state as defined in Annex 9. Paragraph 2.7. adds Annex 9 for adhesion on wet surfaces of class C1 tyres in worn state to the definition of “Representative tyre size”. Paragraph 3.1.1. adds “adhesion performance level on wet surfaces of a tyre in worn state” to the performance characteristics to be assessed.

Paragraph 6.4.1. gives wet grip index (GB) limits for class C1 tyres tested in accordance with either procedure in Annex 9. The minimum GB is 0.88 for a normal tyre and 0.80 for a snow tyre; it is not defined for a special use tyre. For “snow tyres for use in severe snow conditions” with a speed category symbol for more than 160 km/h, the minimum GB is 0.80. With a speed category symbol for not more than 160 km/h, the minimum GB is 0.70, and for ice grip tyres it is 0.70. For normal tyres with speed category symbol for 300 km/h or more and aspect ratio 40 or lower, the limit decreases by 0.08. Verification tests for approvals under paragraph 6.4. must use the same Annex 9 testing method as the original approval (paragraph 8.3.3.).

Annex 9 defines a “tyre in worn state” as a new tyre artificially worn to the tread-wear indicator height of UN Regulation No. 30. In the central zone, the final groove depth must be 2 mm ± 0.4 mm at each measurement point and 2 mm ± 0.2 mm on average. In the shoulder zone, the final groove depth must not be greater than 2 mm. The wet grip braking performance of the candidate tyre in worn state is compared to the reference tyre, by the vehicle or trailer method. The reference tyre in worn state is the Standard Reference Test Tyre SRTT16 in worn state. Appendices 1 and 2 give a worn tyre preparation report example and test report examples of wet grip index for tyres in worn state.

The stage 1 tables for rolling sound emissions of class C1, C2 and C3 tyres are deleted from paragraphs 6.1.1. to 6.1.3. These paragraphs now refer to “the values given below” in place of “the values pertinent to the applicable stage given below”. Paragraph 6.3.1. with the stage 1 rolling resistance limits is deleted. The stage 2 maximum values for the rolling resistance coefficient are now part of paragraph 6.3. In paragraph 5.2.2., S and R are now followed only by the suffix “2” for compliance to stage 2. The suffixes S1 and R1 are deleted from the list in paragraph 5.4.3.

New suffix “B” identifies additional conformity to the requirements on adhesion on wet surfaces of tyres in worn state (paragraph 5.2.2.). Suffix “W” now refers to adhesion on wet surfaces of tyres in new state. In paragraph 4.3.1., the example now uses the 03 series: “0236378 + 03S2WR2B”. Annex 2, Appendix 4 now shows an 02 series approval extended under the 03 series to wet adhesion of tyres in worn state. New footnotes: approvals to UN Regulation No. 117 for tyres within the scope of UN Regulation No. 54 currently exclude the worn-state wet adhesion requirement. Annex 1 adds item 8.3. for the wet adhesion level of tyres in worn state (GB).

Former paragraph 6.4. and its subparagraphs become paragraph 6.5. and its subparagraphs. Former paragraphs 6.5., 6.5.1., 6.6. and 6.7. become 6.6., 6.6.1., 6.7. and 6.8. The references in paragraphs 2.13.1. and 6.6. and in Annex 7, Appendix 3 now use the new numbers. In Annex 1, former items 8.3., 8.4. and 8.4.1. become 8.4., 8.5. and 8.5.1. Paragraph 6.2. and the titles of Annex 5 and its appendix now refer to the wet adhesion of tyres in new state.

From the official date of entry into force of the 03 series, Contracting Parties must not refuse to grant or accept 03 series type approvals. Contracting Parties must continue to accept and extend 02 series approvals of C2 and C3 tyres, which the worn-state wet adhesion changes do not affect. As from 7 July 2024, Contracting Parties need not accept 02 series approvals of class C1 tyres first issued after 7 July 2024. Until 7 July 2026, they must accept those approvals first issued before 7 July 2024 (paragraph 12.4.). As from 7 July 2026, they are not obliged to accept 02 series approvals of class C1 tyres (paragraph 12.5.). Until 1 September 2024, Contracting Parties may continue to grant 03 series approvals based on the Annex 7 snow test with SRTT14 (paragraph 12.7.).