For tax purposes, leasing may seem more advantageous when you use your vehicle for business; although it is your choice and I recommend that you enter both "choices" in TurboTax and see which one specifically helps you.
The actual deductions depend whether you will choose to use Standard Mile method or Actual Expenses method when deducting your car...A down payment is never tax deductible (for purchased or leased cars) because the amount simply reduces your original cost.
If you choose to use a
Standard Mileage Rate (54 cents per mile for 2016) - your car operating
expenses (gas, oil, tires, lease payments etc.) are "sort of" included in that rate; so all you deduct is miles driven for business purposes at the rate given by the IRS
If you use Actual
Expenses method - leasing a car may be more advantageous... you can deduct your actual car expenses such as lease payments, oil, gas repairs but you cannot depreciate the car. Since you will use 90% for business, 90% of your actual costs will be deductible. If you purchase the car, you can't deduct the payments, but you can depreciate your car and can deduct the interest on the car's loan based, of course, on the percentage of your business use. The reason why I think leasing is better, is because you may have a taxable gain due to depreciation when you ever dispose/stop using the car for business; if you just return the leased car back to the dealer, there is no taxable gain.
I found this article that I like; it gives detail comparison on your topic: http://blog.turbotax.intuit.com/tax-tips/buy-or-lease-your-new-business-vehicle-67/
In TurboTax, when
general business information and business income is entered, you will arrive at
the Business Summary Screen. Business Use of Vehicles is a section to enter
your car expenses. The program will ask
you some general questions about the car, business miles for the car. You will be able to enter your expenses and see which method is more beneficial.
