What year are we talking about?
If you used a personally owned vehicle for business in 2023, the business can reimburse you for your vehicle use. If the business has an accountable expense plan, the reimbursement is tax-free to you and is a business expense deduction for the business. If the business does not have an accountable expense plan, the business can still reimburse you for the use of a personal vehicle, but the reimbursement is taxable income to you (on your W-2 if you are an employee), and is deductible for the business as part of your wages.
Methods for deducting vehicle expenses, and the rules for accountable expense plans, are covered in publication 463, chapter 4.
https://www.irs.gov/pub/irs-pdf/p463.pdf
