There's not an easy answer here. See reference below.
It depends on your "intent". If you have a profit motive, in renting them your truck, you may deduct your expenses. If you are doing it for your own convenience, your expenses are not deductible, and the amount on the 1099-Misc is taxable. If you do deduct expenses, be sure to deduct less than the total paid so that you show a profit.
Yes, I would deduct the standard mileage deduction and then subtract the value of the provided fuel and maintenance from that. But, you will find no IRS guidance on that. Mileage, from your home, to the first job site and mileage home from the last job site of the day are not deductible. That's considered commuting. If you go to the shop first, then to the job site, the mileage to the shop is not deductible.
If you're going to claim the deduction, Do not enter the 1099-Misc, at the 1099-Misc screen. Instead, enter at:
In TurboTax (TT), enter at:
- Federal Taxes tab (Personal in Home & Business)
- Wages & Income
Scroll down to:
-Less Common Income
-Misc Income, 1099-A, 1099-C
- On the next screen, choose – Income from renting out personal property - click start and enter your income and expenses on the next screen. Note: do not enter more expenses than income. You are not allowed to claim a loss. Also note that you have to hand calculate your total expenses. You can't just enter mileage. The IRS rate for 2019 is $0.58 / mile.
The gross income will be included on line 8 of Schedule 1, and identified on the line to the left of line 8. The deduction will be sort of "hidden". It's included in the line 22 (of schedule 1) total with the code "PPR" to the left.
Referece:
https://www.thebalance.com/car-rental-income-3193073
