Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

mortgage vs car loan vs invest extra cash?
First off, the "mortgage interest is tax deductible" argument is a red herring.  What "tax deductible" sounds like it means is "if I pay $100 on X, I can pay $100 less on my taxes".  If that were true, you're still not saving any money overall, so it doesn't help you any in the immediate term, and it's actually a bad idea long-term because that mortgage interest compounds, but you don't pay compound interest on taxes. But that's not what it actually means.  What it actually means is that you can deduct some percentage of that $100, (usually not all of it,) from your gross income, (not from the final amount of tax you pay,) which reduces your top-line "income subject to taxation."  Unless you're just barely over the line of a tax bracket, spending money on something "tax deductible" is rarely a net gain. Having gotten that out of the way, pay down the mortgage first.  It's a very simple matter of numbers: Anything you pay on a long-term debt is money you would have paid anyway, but it eliminates interest on that payment (and all compoundings thereof) from the equation for the entire duration of the loan.  So--ignoring for the moment the possibility of extreme situations like default and bank failure--you can consider it to be essentially a guaranteed, risk-free investment that will pay you dividends equal to the rate of interest on the loan, for the entire duration of the loan. The mortgage is 3.9%, presumably for 30 years.  The car loan is 1.9% for a lot less than that.  Not sure how long; let's just pull a number out of a hat and say "5 years." If you were given the option to invest at a guaranteed 3.9% for 30 years, or a guaranteed 1.9% for 5 years, which would you choose?  It's a no-brainer when you look at it that way.