If you own the vehicle, then I believe that the best—and possibly only—option, is for the business to reimburse you under an accountable plan. An accountable plan means that the business reimburses you for legitimate business use of the vehicle that you prove to the business with receipts and other records. The business can either reimburse your exact expenses or it can reimburse you using the standard mileage rate. To reimburse under the standard mileage rate, you would keep a list of business trips with the mileage and provide this to the business. With the exact expense method, you would need a list of business trips and business mileage, and you would also need receipts for all the vehicle expenses, and proof of the total annual vehicle vehicle mileage. You would be reimbursed for a percentage of your total actual expense equal to the percentage of total annual vehicle miles that were for the business. Allowable expenses include fuel, repairs and maintenance, insurance, depreciation(for wear and tear), and interest on the vehicle loan but not the principal payments of your vehicle loan. (That’s what depreciation is for.)
Your vehicle use records must be gathered in a timely manner, which means close enough to the events in question that your memory and records are likely to be reliable. You might choose to get reimbursed monthly for example. You could get advance allowances for the vehicle expenses, but for the plan to be considered an accountable plan, you must eventually reconcile the advance payments with your actual expenses and re-pay any amount that was in excess of your actual expenses.
if you use an accountable plan to be reimbursed for vehicle expenses, then the expenses are a deductible expense for the business, and they are not taxable income to you, the vehicle owner. This way, the vehicle expenses are shared equally by all the members of the LLC, which is the correct way to run your business assuming the vehicle really is used 100% for legitimate business activities. Unless this is a distinctive and unique vehicle, like an ice cream truck or a panel van that has been built out with shelves for equipment and parts stock, chances are you will use the vehicle for at least some personal purposes, it’s almost unavoidable. An accountable plan with proper mileage records ensures that the other business owners are not subsidizing your personal use, even if it is only occasional.
see publication 463 for information about vehicle expenses and accountable reimbursement plans.
https://www.irs.gov/pub/irs-pdf/p463.pdf
