CO2 emission characteristics of China VI hybrid vehicles.

[Display omitted] As the ownership of hybrid vehicles soars, accurately predicting and assessing CO 2 emissions become crucial. This study utilized the AVL portable emission measurement system (PEMS) to reveal the actual CO 2 emission of three types of hybrid vehicles. Firstly, engine speed is a key factor influencing CO 2 emissions of range-extended electric vehicle (REEV) and plug-in hybrid electric vehicle (PHEV), while vehicle specific power (VSP) affects HEV. Secondly, in terms of fuel consumption, when the battery levels of REEV and PHEV are low, their fuel consumption tends to be higher than that of HEV. Specifically, the CO₂ emission factor (the amount of CO 2 emitted by a vehicle per unit distance during operation) ratios of REEV to PHEV range from 1.19 to 1.89, while the ratios of REEV to HEV are between 1.41 and 2.57. Thirdly, in terms of NO X control, HEV performed significantly worse. [ABSTRACT FROM AUTHOR]