Beyond linearity: asymmetric effects of service factors on electric vehicle user satisfaction across powertrain types

The sustainable growth of electric vehicles (EVs) depends on user satisfaction and a deeper understanding of its driving factors. Although many studies have examined EV satisfaction, most have assumed a linear relationship between service factors and user satisfaction. This assumption overlooks potential nonlinear attributes. Additionally, few studies differentiate between powertrain types. Using data from Chinese EV users, this study integrates penalty-reward contrast analysis and machine learning to examine the asymmetric influences of service factors on satisfaction with four powertrain types: mini battery electric vehicles (mini-BEVs), full-size BEVs, plug-in hybrid electric vehicles (PHEVs), and range-extended electric vehicles (REEVs). The results show that while brand is the most important predictor of user satisfaction with all four types, its influence patterns differ: it is a symmetric factor for full-size BEVs and REEVs, a satisfier for mini-BEVs, and a dissatisfier for PHEVs.. Conversely, EV promotion policies have the least impact and act as an exciting factor. Moreover, mini-BEV users prioritize cost whereas users of full-size BEVs, PHEVs, and REEVs emphasize vehicle performance. Furthermore, while public charging is critical for BEVs, pre-sale service quality strongly influences REEV satisfaction. This study also provides improvement priorities and goals across the four powertrains. These findings offer valuable policy implications for promoting EV market penetration.