There are two ways to handle deductions for automobiles. Generally, you have to keep track of all your expenses and deduct the total when you file your taxes. For automobiles this would include gas, repairs, car registration, lease payments, depreciation, among others. However, for vehicles there is a standard IRS mileage deduction that you can use as an alternative. For 2021, that rate is $0.56 per mile of business use. You can calculate both to see which results in more savings, but many prefer the standard IRS mileage deduction for its simplicity.