For Sch C, I understand you have an option to choose either Actual Expenses, or Mileage Rate. =>>correct; there are two ways to deduct biz use auto travel expenses expenses, the standard mileage rate or the actual vehicle expenses.you can use either one of them.
1) Can you switch between these methods year after year? What are the restrictions? =====>>>>>I don’t think so; if you’ve already started using the actual cost method for your business car,then You cannot switch to standard mileage rate in later years. Although if you started by using the standard cost method, you can switch to the actual cost method.You cannot use the standard mileage rate if you have used the actual expense tax deduction and claimed the accelerated depreciation deduction in previous years. If you use the standard deduction the first year, you can switch to actual expenses. You have to be very careful because you can lose the ability to switch between standard and actual.as you can see, you need to use actual expenses once you used the actual expense calculation when your vehicle was first used for business purposes. If your vehicle has very high operating costs and low gas mileage, then taking the actual expense deduction may produce better savings for you.however, aslongas your vehicle gets great gas mileage, then taking the mileage deduction will likely be more beneficial for you.