Deductions & credits

You need to determine the cost of the vehicle for business purposes and subtract the depreciation equivalent of the mileage allowance you took over the years to arrive at the adjusted basis. Then, you subtract that amount from the portion of the sales proceeds that apply to the business use of the vehicle and that is your taxable gain or deductible loss.

Here are the depreciation equivalents that you multiply by the mileage you claimed each year to arrive at your depreciation amount:

So, basically you have to multiply the cost of the vehicle by the percentage of time you used it for business versus personal use  to arrive at the cost. Then subtract the depreciation from that to get the basis. Then multiply the sales proceeds by the business use percentage to get the business sales proceeds. Just enter those numbers in TurboTax when you go through the sales entries for the vehicle.