JASIC presents Stage 1 findings on worn tyre wet performance testing precision improvement. JASIC proposes that the KPI target should be the same weighted value as wet grip for new tyres (100% improvement), compared to ETRTO’s 50% improvement target. Stage 1 weighted analysis results show 50% improvement, or 100% improvement if coefficients of the GB formula are revised. The 2019-21 dataset is outside Stage 1 assessment scope due to unmet prerequisites such as buffed SRTT tyre application and reduced sample sizes. JASIC proposes revising GB calculation formula coefficients for the trailer method based on Stage 1 data, with continuous investigation to follow.