UN R117 change reports — Tyres rolling resistance, rolling noise and wet grip
UN Regulation No. 117 (ECE R117) — Uniform provisions concerning the approval of tyres with regard to rolling sound emissions and/or to adhesion on wet surfaces and/or to rolling resistance.
04 series
- 04 series — Supplement 4
Paragraphs 1.3., 2.21., 3.1.1.1. and 5.7. to 5.10. on tyre abrasion are deleted. Annex 10, the procedure for determining the abrasion performance of tyres of class C1, is also deleted with all its appendices.
- 04 series — Supplement 3
In Annex 9, the reference tyre BFCave,corr must now be “greater than or equal to 0.42 and less than or equal to 0.64”, and µpeak,corr “greater than or equal to 0.50 and less than or equal to 0.75”. Until 6 July 2026, Contracting Parties may continue to grant class C1 approvals with Annex 9 tests and Supplement 2 surface friction (paragraph 12.27.). New Annex 9 paragraph 2.3.1.6. covers water depth measurement for external watering.
- 04 series — Supplement 2
The Regulation now also applies to C1 tyres in new state with regard to their tyre abrasion, as defined in paragraph 1.3. Starting from 1 January 2027, the manufacturer must communicate the abrasion level during the approval of new types of class C1 tyres.
- 04 series — Supplement 1
New paragraph 12.17. covers new tyres manufactured before the date in paragraph 12.5. and approved to the 02 or 03 series of amendments. Until 6 January 2029, Contracting Parties applying this Regulation must continue to allow fitting of these tyres on a vehicle in use.
- 04 series — Base text
Paragraphs 6.2.1. to 6.2.3. add stage 2 wet grip limits for tyres in new state, and paragraph 6.3. adds stage 3 rolling resistance limits.
03 series
- 03 series — Supplement 2
Paragraph 2.18. adds the reference tyres “SRTT19.5 siped” and “SRTT22.5 siped”. The wet grip index of class C2 and C3 tyres and the snow grip index in paragraph 4.8.4. now include a factor f.
- 03 series — Supplement 1
A “tyre for use in severe snow conditions” can now be a snow tyre or a special use tyre (paragraph 2.13.1.).
- 03 series — Base text
New paragraph 6.4.1. sets wet grip index (GB) limits for class C1 tyres in worn state, tested with the new Annex 9 procedure.
02 series
- 02 series — Supplement 18
Paragraph 2.18. now refers to ASTM F2872 – 25 for SRTT16C, F2871 – 25 for SRTT19.5 and F3678 – 25 for SRTT19.5 siped.
- 02 series — Supplement 17
Paragraph 2.16.1. now defines “principal grooves” as the wide tread grooves positioned in the central zone of the tyre tread. The central zone is “the area on the tread which comprises of 75 per cent of the width of the tread measured symmetrically from the centre line”. New paragraph 2.16.2. defines “tread groove”.
- 02 series — Supplement 14
A class C1 snow tyre for use in severe snow conditions needs a minimum ice grip index of 1.18 for classification as ice grip tyre.
- 02 series — Supplement 13
Annex 5 has new wet grip index formulas, and its track characterization now uses the Standard Reference Test Tyre SRTT16.