I would be quite careful in your calculations. A 17 year-old pickup (by your statement, I'm assuming you had it the entire time?) would be depreciated out and the basis would be zero.
Using the standard mileage rate implies that it was part business and part personal. If that is the case, any calculation would need to compare the business portion of the cost of the pickup, and the personal portion. The depreciation portion of the standard mileage rate would be deducted from the business portion of the cost of the pickup to arrive at the basis at the time of loss.
SECTION 4. BASIS REDUCTION AMOUNT
For automobiles a taxpayer uses for business purposes, the portion of the
business standard mileage rate treated as depreciation is 24 cents per mile for 2016, 25
cents per mile for 2017, 25 cents per mile for 2018, 26 cents per mile for 2019, and 27
cents per mile for 2020. See section 4.04 of Rev. Proc. 2019-46.
If that is zero or below cost, there is no business loss. Any loss would then be personal.
**Disclaimer: Effort has been made to offer correct information; but due to the discussion forum limitations, the poster disclaims any legal responsibility for the accuracy of the poster's response**
