Overview
ISO 18164:2005 defines laboratory methods for measuring rolling resistance of new pneumatic tyres designed primarily for passenger cars, trucks, buses and motorcycles. Tests are carried out under controlled conditions (drum dynamometer), producing measurements such as the rolling resistance (N·m/m) and the rolling resistance coefficient (Cr). The standard clarifies that measured values are not a direct indicator of vehicle fuel economy or overall tyre quality.
Key topics and technical requirements
- Scope: Applies to all passenger car, truck, bus and motorcycle tyres in new condition; measurements compare tyres free‑rolling, straight ahead and perpendicular to the drum surface.
- Test methods: Four alternative measurement techniques are permitted - force, torque, power and deceleration methods; each result is converted to a force at the tyre/drum interface.
- Drum and equipment:
- Minimum drum diameter: ≥1.5 m (passenger car & motorcycle; reference 1.7 m), ≥1.7 m for truck/bus tyres.
- Drum surface: smooth steel or textured (kept clean); drum width must exceed tyre tread width.
- Instrumentation and control accuracies are specified (see Annex C) because rolling resistance involves measuring very small forces amid larger loads.
- Test conditions:
- Ambient reference temperature 25 °C (axis measurement 1 m away from sidewall); temperature corrections available per Clause 9.2.
- Inflation: capped or regulated inflation methods defined; inflation pressures and caps follow Table 2.
- Speeds: single and multiple test speed regimes (e.g., passenger car multiple speeds: 50, 90 and 120 km/h; common single speed 80 km/h).
- Preconditioning: break‑in, thermal conditioning (typically hours), pressure adjustment, warm‑up and steady‑state measurement steps.
- Data handling: Parasitic loss measurement, calculation of rolling resistance, temperature and drum diameter corrections, and data analysis methods (Clauses 7–9 and Annexes A–C).
Practical applications and users
ISO 18164 is used by:
- Tyre manufacturers for R&D, product comparison and internal validation of rolling resistance.
- Independent test laboratories and tyre test facilities using dynamometers.
- Vehicle manufacturers and OEMs comparing tyre options for vehicle development.
- Regulatory bodies and researchers studying tyre energy loss and lab measurement repeatability.
Benefits include standardized comparison of tyre rolling resistance, repeatable lab procedures, and guidance on equipment and corrections for accurate, comparable results.
Related standards
Keywords: ISO 18164, rolling resistance, tyre testing, rolling resistance coefficient, dynamometer, tyre measurement, tyre R&D.