According to the IRS form instructions for line 9 of Schedule C (Form 1040): You can deduct the actual expenses of operating your car or truck or take the standard mileage rate.This is true even if you used your vehicle for hire (such as a taxi-cab). You must use actual expenses if you used five or more vehicles simultaneously in your business (such as in fleet operations).ccording to the IRS form instructions for line 9 of Schedule C (Form 1040): You can deduct the actual expenses of operating your car or truck or take the standard mileage rate.