I'm assuming you own a business and the asset has been depreciated through a Sch F or Sch C or some other business.
Because you use it for business the sale is reported on the Form 4797. The best thing to do is buy a replacement car/truck and then treat it as a like kind exchange. Which is reported on the Form 8824. There you will have to run through a computation on a worksheet which will give you the basis (for depreciation purposes) of the replacement vehicle. 2020 Instructions for Form 8824 (irs.gov)
