Proposal to ensure robust tyre abrasion measurements regardless of the test method used.

Proposal to establish a list of test facilities deemed equivalent pursuant to paragraph 12.8 of the draft UN Regulation on tyre abrasion. The list recognizes six foundational facilities that participated in the initial inter-facility campaign to develop abrasion limits for C₁ tyres. The facilities are: DEKRA Test Center SA (France, circuit); IFV (Germany, circuit); Link Engineering Company GmbH (Germany, circuit); Bridgestone Corporation (Japan, indoor drum); Sumitomo Rubber Industries, LTD. (Japan, indoor drum); and The Yokohama Rubber Co., Ltd. (Japan, indoor drum). These facilities generated foundational data used to define abrasion limits and are deemed equivalent for equivalence procedures under Annex 4.

The document establishes procedures for demonstrating equivalence between vehicle circuit and indoor drum test facilities. It defines requirements for selecting exercise tyres and participating facilities, establishing baseline values from multiple facilities, and comparing facility results against baselines. For indoor drum facilities, transfer functions mathematically relate drum results to vehicle results, either as generic (fixed coefficient) or specific (facility-determined coefficient). Facilities must meet statistical criteria including result deviation limits and root mean square deviation thresholds to demonstrate equivalence.