<prompt> Human: 25000 principal if I finance. I can get a rate of 3.05 for 60 months. Down payment of 5k, but thats neither here nor there in this case Total amount paid after 5 years is 26,986 by my calculation.I can get 2.6 on that 25k in a 60-month CD. Total value after 5 years is 28,466. Even accounting 30 taxes on the interest, Im still about 500 ahead. Anything Im missing here? Sounds borrowing in this case would literally be free money, albeit a relatively small amount that I wont see for another 5 years. Assistant: paying out 3.05 APR interest receiving in 2.6 APR interest thinks this is profitableYour math is wrong. Specifically, the error youre making is that in the second case borrow invest you also have to come up with the monthly auto loan payment amounts, or you need to have invested less in the CD. In effect youre comparing apples and oranges.Case 1 - cash buy - 25000 spentCase 2 - finance and invest - 25000 all monthly payments spentYoure comparing the INCOME from investing 25000 PLUS all monthly payments to the OUTGO from borrowing 25000. Thats the only reason it appears to be positive.Compare APRs. Borrowing money at 3.05 to invest at 2.6 doesnt do anything good for you.Human: Incorrect, Case 1 is 25k spent minus opportunity cost of 25k investment. And a loan principal decreases with time while investment principal increases.  <response>: If you didnt want to learn anything, why post? Go ahead and borrow at 3.05 and invest at 2.6 then, youll make a ton of money. Is that what you want to hear?EDIT: LETS DO THE MATH. Assume you have 50K in cash, and a demand investment that yields 2.6 not locked in like a CD. Makes it easier.CASE A Put 50K in investment, dont buy car. After five years, you have 56,933.41.CASE B Buy car with 25K, invest remaining 25K. After five years, you have 28,466.71. The difference between A and B, 28466.70, is effectively how much it cost you to buy that car, over five years.CASE C Borrow another 25K at 3.05, hand the borrowed money to the car dealer for the car. Invest all 50K in the 2.6 investment, withdrawing money from it every month to make the loan payments. At the end you have 28070.68.The difference between B and C is what it will cost you to finance the car. About 400. If you borrow money 25K at 3.05 and invest it at 2.6, for five years, youll end up losing about 400 over not doing that. Note that this difference is constant no matter how much money you start with. 