When using the "per-mile" deduction, depreciation is built into that. It's important that you "KEEP TRACK" of your total miles for each year, because when you sell or trade the vehicle, you will need to recapture that depreciation.
Since the per-mile deduction changes every year, so does the portion that is depreciation. If you take a look at https://bradfordtaxinstitute.com/Free_Resources/IRS-Mileage-Rates.xml.aspx about halfway down the page is the "depreciation per-mile" going back to tax year 2003
