The central factor when determining what your monthly payment will be (other than the interest rate and the down payment amount) is the term (length) of the loan. Shorter online auto loan terms will result in higher payments, but you will also pay less for your new vehicle in the long run because the amount of interest will be less. Keep the loan term as short as you can afford it for. If you think your financial situation may possibly go downhill (given the current economy), you can choose the longer term while making payments based off the shorter term without any interest penalty since all online auto loans are simple interest loans. To help you out, many online auto loan sites (driverslane.com) have calculators that can help you with your budget as well as calculate early loan pay-off situations.