Yes you will pay interest unless you have some special exceptions in your loan as mentioned above by jaegar66. Something like no-interest payments for 12 months or deferred interest for the first 12 months would allow you to repay the loan in 12 months without paying any interest. Those kinds of exceptions are rather rare in car loans though, more common to see those types of loans at places like BestBuy or Sears when they advertise 0% financing for 6 or 12 months.