prBAS ISO 20908:2026

This document specifies methods for measuring tyre-to-road sound emissions from tyres fitted on rig that applies the tyre on a rotating drum under coast-by conditions (i.e. when the tyre is in free‑rolling, non‑powered operation). The specifications are intended to achieve a correlation between results of testing the exterior noise of tyres in a semi anechoic chamber and outdoor testing as described in ISO 13325. This document is applicable to passenger cars and light commercial vehicles tyres as defined in 3.1. It is not intended to be used to determine the sound contribution of tyres applying a torque, nor for the determination of traffic sound nuisance at a given location.