Tyre rolling resistance is a fundamental parameter in automotive engineering, directly impacting vehicle fuel efficiency and overall performance. The Rolling Resistance Coefficient (CRR) is influenced by tyre construction, material properties, and operational conditions such as inflation pressure, vehicle speed, load, ambient temperature, and road surface roughness. This study investigates the influence of critical parameters—including test speed, inflation pressure, load, temperature, and slip angle—on the rolling resistance of tyres of various sizes. While previous research has predominantly focused on radial tyres, this paper extends the analysis to include bias-ply tyres, which remain widely used in ASEAN countries, including India. The findings aim to offer valuable insights for policymakers and researchers by examining the behaviour of bias tyres under real-world conditions. Special focus is given to the influence of slip and camber angles, with experiments conducted on passenger