For 2018, the standard mileage rates for the use of a car (also vans, pickups or panel trucks) are:
A taxpayer may not use the business standard mileage rate for a vehicle after using any depreciation method under the Modified Accelerated Cost Recovery System (MACRS) or after claiming a Section 179 deduction for that vehicle. In addition, the business standard mileage rate cannot be used for any vehicle used for hire or for more than four vehicles used simultaneously.
Taxpayers always have the option of calculating the actual costs of using their vehicle rather than using the standard mileage rates. Note that if you want to use the standard mileage rate for a car you own, you must choose to use it in the first year the car is available for use in your business. Then in later years, you can choose to use either the standard mileage rate or actual expenses.