ISO 10521-1:2006 specifies methods of determining the road load of road vehicles for subsequent test purposes, for example, fuel consumption tests or exhaust emission measurements. This determines the road load of a vehicle running on a level road under reference atmospheric conditions. It is achieved by either the coastdown method, the torquemeter method or the wind-tunnel/chassis-dynamometer method.

ISO 10521-1:2006 is applicable to motor vehicles, as defined in ISO 3833:1977, up to a gross vehicle mass of 3 500 kg.