Does the questioner want to ask "How much is the interest rate for a three-year installment of a 50,000 Yixin car loan?" 10,500 yuan. To calculate the installment interest of a car loan, you can use the formula, 50,000*7%*3 years = 10,500 yuan. With the principal data of a 50,000 yuan car loan, you only need to know the car loan interest rate and loan period to calculate the installment interest. Calculated based on the annual loan interest rate of 7% and the loan period of 3 years, the installment interest = car loan principal × interest rate × loan period.