The lateral and longitudinal dynamics of passenger car tyres are critical to overall vehicle safety, handling, and stability. These characteristics directly influence braking, acceleration, and cornering performance. This study investigates the impact of key input parameters, namely inflation pressure, vertical load, and inclination angle, on tyre behaviour using a dual approach: Indoor testing with a Flat-Trac CT+ (FTCT+) and Outdoor evaluation using a skid trailer.
Lateral dynamics are evaluated at slip angles to analyze lateral force and aligning moment characteristics. The influence of inclination angle, pressure, and load is quantified through cornering stiffness and aligning stiffness. The tests are conducted in both sweep and steady-state modes. To maintain data consistency, all tests use tyres of a single specification sourced from the same production batch.
Longitudinal behaviour of a tyre is characterized by various parameters such as peak friction coefficient, sliding friction coefficient, and longitudinal slip stiffness. Comparisons between indoor and outdoor environments offer insight into the variability and consistency of test results under controlled versus real-world conditions.
The study compares tyre performance using FTCT+ indoor testing and Skid Trailer outdoor evaluations, including an analysis of steady vs transient behaviour on FTCT+. Steady-state tests showed consistently higher cornering and aligning stiffness, by up to 9.1% and 24.1%, respectively, across different camber angles and inflation pressures. Similarly, FTCT+ yielded higher brake Mu peak (10-16%) and longitudinal slip stiffness values (30-50%), against outdoor results. The key trends identified in these variations provide insights on how various input parameter and test environments influence the tyre performance and offer input for the advancements of test methodologies.