ISO 23274-2:2012 specifies a chassis dynamometer test procedure to determine the end of CD (charge-depleting) state and consumed electric energy during CD state.

The identification of the end of CD state is an important step for procedures to determine exhaust emissions and fuel consumption. Final determination of exhaust emissions and fuel consumption is not included in ISO 23274-2:2012.

ISO 23274-2:2012 applies to vehicles with the following characteristics.

• The vehicles are hybrid-electric road vehicles (HEV) with an internal combustion engine (ICE) and the on-board rechargeable energy storage system (RESS) for vehicle propulsion which is supplied by electric energy from the stationary external power source.
• A CD state, in which the electric energy in RESS from the stationary external power source is consumed, is followed by a CS (charge-sustaining) state in which the fuel energy is consumed sustaining the electric energy of the RESS.
• Only batteries are assumed as the RESS of a vehicle.
• The RESS is not charged while driving unless by regenerative braking and/or by generating by ICE.
• The vehicle is classified as a passenger car or light duty truck, as defined in each regional annex.
• Only liquid fuels (for example, gasoline and diesel fuel) are used.

Trolleybuses and solar powered vehicles are not included in the scope.

In the case of vehicles with ICE using other fuel [for example, compressed natural gas (CNG), hydrogen (H2)], ISO 23274-2:2012 can apply except the measurement of consumed fuel; otherwise the measurement method for those using the corresponding fuel can apply.