Study evaluating the validity of the current recommendation in Annex 3 Appendix 5 for sandpaper surface replacement interval based on running distance by examining test results exceeding 20,000 km. Testing nine consecutive runs on #80 grit sandpaper without replacement over 45,000 km total distance using new tyres for each run. Surface roughness measured by MPD and micro roughness showed no significant change and satisfied requirements in Paragraph 2.4.2.3. SRTT17S abrasion level remained above specification limits. Reproducibility of Abrasion Index was maintained when compared with Market Assessment results. Proposes extending replacement interval from 20,000 km to 30,000 km for 2-position drums and from 40,000 km to 60,000 km for 1-position drums.

Agenda for the 53rd TFTA session on 29 October 2026. Items include approval of previous meeting minutes, outcome from GRPE 95th session, status of TADG drafting C1 and C2 provisions, ETRTO proposals for UN R186 updates, C1 circuit SRTT abrasion level range, C2 test campaign status, C3 brainstorming on virtual testing and tyre type definition optimization, and funding and resource allocation discussion.

Proposal to suppress the loading restriction to 85% of vehicle payload, allow several propulsion energy converters, allow mixing different transmission architectures, include circuit abrasion level measurement possibilities for snow tyres not measuring Severe Snow Tyres, and establish new circuit abrasion level limits based on 17 circuits in the 2026 Confirmation plan. ETRTO is testing acceleration correction, fully loaded vehicles, different energy converters and transmission architectures, alignment specifications for various vehicle types, and load distribution management to reduce test uncertainties and improve method efficiency. An informal document will be proposed in January 2027.

Update proposal for UN R186 to modify load distribution in para. 1.6.2 to apply only to C₁ tyres and add minimal ballast requirement for C₂ tyres, update temperature ranges in para. 1.10.4 for normal and snow tyres, and develop alignment prescriptions for C₂ tyres. The proposal describes a test concept using convoys of up to 4 vehicles with single tyres up to 3.5T GVW under controlled driving conditions to determine tyre abrasion level index. SRTT usage strategy and market assessment to be finalized following temperature testing results.

Status report on the Tyre Abrasion Drafting Group’s progress across sessions 14–16 in 2026. Work includes proposed editorial amendments to UN R186 covering removal of special use tyre references, alignment of symbols between vehicle and drum test methods in Annex 3, updates to ASTM standard references, clarification of introductory provisions, reordering of vehicle requirement paragraphs, splitting of vehicle and circuit requirement paragraphs, updates to test load definition, reworded alternative test program description, removal and correction of duplicate drum control system requirements, and sandpaper surface replacement provisions. Circuit and drum abrasion level ranges require further review by the Task Force on Tyre Abrasion.