ISO 23274:2007 establishes a uniform chassis dynamometer test procedure for hybrid-electric road vehicles (HEV) with internal combustion engines (ICE) classified as passenger cars and light duty trucks, as defined in each regional annex. ISO 23274:2007 proposes ways of correcting the measured emissions and fuel consumption of HEV, in order to obtain the correct values when the battery state of charge (SOC) of the rechargeable energy storage system (RESS) does not remain the same between the beginning and the end of test cycle.ISO 23274:2007 applies to HEV with ICE of which the nominal energy of the RESS is at least 2 % of the total energy consumption by the vehicle over the test cycle.ISO 23274:2007 applies to non-externally chargeable vehicles without an operating mode switch to draw propulsion energy from the following sources of energy: consumable fuel, and an energy storage battery/capacitor system that is rechargeable only by an on-board engine-generator/electric motor system.Consumable fuels covered by ISO 23274:2007 are limited to petroleum-based liquid fuels (e.g. gasoline and diesel fuel).