Proposal to establish a harmonized method for determining system power ratings of hybrid electric vehicles and pure electric vehicles with multiple propulsion energy converters. The GTR specifies two test procedures (TP1 and TP2) to measure power at defined reference points analogous to conventional engine output shafts. TP1 measures electrical power and estimated ICE power; TP2 measures torque and speed at axles or wheel hubs. The procedure identifies reference points based on powertrain architecture, requires manufacturers to provide verifiable K factors for energy conversion efficiency, specifies measurement accuracy requirements, and includes validation criteria. The GTR applies to vehicles in categories M₁-M₂ and N₁-N₂ with maximum laden mass not exceeding 3,500 kg, excluding fuel cell vehicles.