How to determain car loan interest?
I can track my mortgage payments from an amortization schedule and see exactly how much I need to pay each month in order to get it paid on in x amount of time (I put this together on an excel spreadsheet). I want to do this with my car loan, but each month the interest is a different rate. One month I see that 36% of my payment went to interest, the next month its 28%, the next month its 31%. Seems to me the best plan would be to send in extra payments during the months that the interest is the lowest so that more goes towards the principal – but how in the world am I supposed to know when they will take more or less interest? Can I ask them to just give me a fixed rate each month?