The U.S. Customer Service Index (CSI) Study is now in its 45th year and has been redesigned for 2025. Along with traditional Voice of the Customer survey data, the study index now includes, for the first time, repair data drawn from individual in-dealership repairs. This repair information, secured from individual dealership service transactions, allows the study to offer an unprecedented level of granularity of both service quality and customer retention.

The study measures satisfaction with service at franchised dealer and aftermarket service facilities for maintenance or repair work among owners and lessees of one- to three-year-old vehicles. It also provides a numerical index ranking of the highest-performing automotive brands sold in the United States, which is based on the combined scores of five measures comprising vehicle owner service experience data and actual repair data. These measures are (in order of importance): service quality; service advisor; vehicle pick-up; service facility; and service initiation. In 2023, model segment rankings were added to the study to differentiate between the service needs for cars, trucks, SUVs and minivans.

The 2025 study is based on responses from 55,210 verified registered owners and lessees of one- to three-year-old vehicles. JD Power goes to great lengths to ensure that survey respondents are true owners of the brand for which they are surveyed. The study was fielded from July through December 2024.