Tyre mass contributes to unsprung mass, rotating inertia, and broader vehicle-related characteristics, yet manufacturing mass variability among nominally identical passenger-car tyres remains comparatively insufficiently documented experimentally. This study investigates manufacturing mass variability in selected groups of new passenger-car tyres using a controlled repeatability-oriented weighing protocol. The primary dataset comprised 68 new passenger-car tyres grouped according to identical nominal specifications and available production characteristics, while six lightweight competition tyres were analysed separately as an auxiliary reference case. Each tyre was measured ten times with repositioning before every measurement under controlled indoor conditions. The observed repeatability remained within approximately 0.1–0.3 g, substantially below the between-tyre differences identified within several analysed groups. Descriptive statistical indicators, including mean mass, range, standard deviation, and coefficient of variation (CV), were used to evaluate within-group dispersion. The results confirmed experimentally detectable manufacturing mass variability among tyres with identical nominal specifications, including measurable differences between production batches of the same nominal tyre group. Among the analysed groups with sample size n ≥ 4, the lowest relative variability was observed for the Continental 275/35R21 tyres (CV = 0.05%), whereas the highest was identified for the summer Kleber 185/65R15 tyres (CV = 0.84%). The results demonstrate that tyre mass variability is experimentally detectable under controlled repeatable conditions and may represent a relevant engineering descriptor of manufacturing consistency.
Damyanov et al. (2026) studied this question.