Finance car with or with out a balloon payment
That interest rate (13%) is steep, and the balloon payment will have him paying more interest longer. Investing the difference is a risky proposition because past performance of an investment is no guarantee of future performance. Is taking that risk worth netting 2%? Not for me, but you must answer that last question for yourself. To your edit: How disruptive would losing the car and/or getting negative marks on your credit be? If you can quantify that in dollars then you have your answer.
Your question has an interesting mix of issues. ASAP and 3-4 years doesn't feel like the same thing. ASAP results in bad decisions made in haste. Four years of living very frugally can create a nice down payment on a house.      A car is only an investment for Uber drivers and those who are directly financially benefitting from a car's use. For everyone else, it's a necessary expense.  What I'd focus on is the decision of buying a plot of land. Unless this is a very common way to do it in your country, I don't recommend that order. Having land and then trying to finance the building of a house has far more complexity than most people need in their lives. In my opinion, the better way is to save the 20% down, and buy a new or existing home you can afford.  In the end, spending is a matter of priority. If you truly want to get out in the least time, I'd save every dime I can and start looking for a house that your income can support. The largest problem and source of anxiety / ruin for homeowners during the housing market collapse was caused by the inability to refinance. Many people had bought homes which they were stretched to afford, by using variable-rate mortgages.  These would typically offer a very attractive initial rate, with an annual cap on the potential increase of rate.  Many of these people intended to refinance their variable-rate to a fixed rate once terms were more favorable.  If their house won't appraise for the value needed to obtain a new loan, they are stuck in their current contract with potentially unfavorable rates in the later years (9.9% above prime was not unheard of.) Also, many people, especially those in areas of high inflation in the housing market, used a financial device known as a Balloon Mortgage, which essentially forced you to get a new loan after some number of years (2, 5, 10) when the entire note became due.  Some of those loans offered payments less than Principal + Interest! So, say you move near Los Angeles and can't afford the $1.2M for the 3-bedroom ranch in which you wish to live.  You might work out a deal with your mortgage broker/banker in which you agree contractually to only pay $500/month, with a balloon payment of $1.4M due in 5 years, which seemed like a good deal since you (and everyone else,) actually expect the house to be 'worth' $1.5M in 5 years. This type of thing was done all the time back in the day.  Now, imagine the housing bubble bursts and your $1.2M home is suddenly only valued at, perhaps, $750k.  You still owe $1.4M sometime in the next several years (maybe very soon, depending on timing,) and can only get approved financing for the current $750k value -- so you're basically anticipating becoming homeless and bankrupt within the same year. That is a source of much anxiety about being upside-down on a loan. See this question for an unfortunate example. "By the sounds of things, you're not asking for a single formula but how to do the analysis... And for the record you're focusing on the wrong thing. You should be focusing on how much it costs to own your car during that time period, not your total equity.  Formulas:  I'm not sure how well you understand the nuts and bolts of the finance behind your question, (you may just be a pro and really want a consolidated equation to do this in one go.) So at the risk of over-specifying, I'll err on the side of starting at the very beginning. Any financial loan analysis is built on 5 items: (1) # of periods, (2) Present Value, (3) Future Value, (4) Payments, and (5) interest rate.  These are usually referred to in spreadsheet software as NPER, PV, FV, PMT, and Rate. Each one has its own Excel/google docs function where you can calculate one as a function of the other 4. I'll use those going forward and spare you the 'real math' equations.  Layout: If I were trying to solve your problem I would start by setting up the spreadsheet  up with column A as ""Period"". I would put this label in cell A2 and then starting from cell A3 as ""0"" and going to ""N"". 5 year loans will give you the highest purchase value w lowest payments, so n=60 months... but you also said 48 months so do whatever you want.  Then I would set up two tables side-by-side with 7 columns each. (Yes, seven.) Starting in C2, label the cells/columns as: ""Rate"", ""Car Value"", ""Loan Balance"", ""Payment"", ""Paid to Interest"", ""Principal"", and ""Accumulated Equity"". Then select and copy cells C2:I2 as the next set of column headers beginning in K2. (I usually skip a column to leave space because I'm OCD like that :) ) Numbers: Now you need to set up your initial set of numbers for each table. We'll do the older car in the left hand table and the newer one on the right. Let's say your rate is 5% APR. Put that in cell C1 (not C3). Then in cell C3 type =C$1/12. Car Value $12,000 in Cell D3. Then type ""Down Payment"" in cell E1 and put 10% in cell D1. And last, in cell E3 put the formula =D3*(1-D$1). This should leave you with a value for the first month in the Rate, Car Value, and Loan Balance columns. Now select C1:E3 and paste those to the right hand table. The only thing you will need to change is the ""Car Value"" to $20,000. As a check, you should have .0042 / 12,000 / 10,800 on the left and then .0042 / 20,000 / 18,000 on the right.  Formulas again: This is where spreadsheets become amazing. If we set up the right formulas, you can copy and paste them and do this very complicated analysis very quickly.  Payment The excel formula for Payment is =PMT(Rate, NPER, PV, FV). FV is usually zero. So in cell F3, type the formula =PMT(C3, 60, E3, 0). Obviously if you're really doing a 48 month (4 year) loan then you'll need to change the 60 to 48. You should be able to copy the result from cell F3 to N3 and the formula will update itself.  For the 60 months, I'm showing the 12K car/10.8K loan has a pmt of $203.81. The 20K/18K loan has a pmt of 339.68.  Interest The easiest way to calculate the interest is as =E3*C3. That's (Outstanding Loan Balance) x (Periodic Interest Rate). Put this in cell G4, since you don't actually owe any interest at Period 0.  Principal If you pay PMT each month and X goes to interest, then the amount to principal is ""PMT - X"". So in H4 type =-F3 - G3. The 'minus' in front of F3 is because excel's PMT function returns a negative amount. If you want to, feel free to type ""=-PMT(...)"" for the formula that's actually in F3. It's your call.  I get 159 for the amount to principal in period 1.  Accumulated Equity As I mentioned in the comment, your ""Equity"" comes from your initial Loan-to-Value and the accumulated principal payments. So the formula in this cell should reflect that. There are a variety of ways to do this... the easiest is just to compare your car's expected value to your loan balance every time. In cell I3, type =(D3-E3). That's your initial equity in the car before making any payments. Copy that cell and paste it to I4. You'll see it updates to =(D4-E3) automatically. (Right now that is zero... those cells are empty, but we're getting there) The important thing is that as JB King pointed out, your equity is a function of accumulated principal AND equity, which depreciates. This approach handles those both.  Finishing up the copy-and-paste formulas I know this is long, but we're almost done.  Rate // Period 1 In cell C4 type =C3.  Payment // Period 1 In cell F4 type =F3.  Loan Balance // Period 1 In cell E4 type =E3-H4. Your loan balance at the end of period is reduced by the principal you paid. I get 10,641.  Car Value // Period 1 This will vary depending on how you want to handle depreciation. If you ignore it, you're making a major error and it's not worth doing this entire analysis...  just buy the prettiest car and move on with life. But you also don't have to get it scientifically accurate. Go to someplace like edmunds.com and look up a ballpark. I'm using 4% depreciation per year for the old (12K) car and 7% for the newer car. However, I pulled those out of my ass so figure out what's a better ballpark.  In G1 type ""Depreciation"" and then put 4% in H1. In O1 type ""Depreciation"" and then 7% in P1. Now, in cell D4, put the formula =D3 * (1-(H$1/12)).  Paste formulas to flesh out table As a check, your row 4 should read 1 / .0042 / 11,960 / 10,641 / 203.81 / 45 / 159 / 1,319. If so, you're great. Copy cells C4:I4 and paste them into K4:Q4.  These will update to be .0042 / 19,883 / 17,735 / 339.68 / 75 / 265 / 2,148.  If you've got that, then copy C4:Q4 and paste it to C5:C63. You've built a full amortization table for your two hypothetical loans. Congratulations.  Making your decision I'm not going to tell you what to decide, but I'll give you a better idea of what to look at. I would personally make the decision based on total cost to own during that time period, plus a bit of ""x-factor"" for which car I really liked.  Look at Period 24, in columns I and Q. These are your 'equities' in each car. If you built the sheet using my made-up numbers, then you get ""Old Car Equity"" as 4,276. ""New Car Equity"" is 6,046. If you're only looking at most equity, you might make a poor financial decision.  The real value you should consider is the cost to own the car (not necessarily operate it) during that time... Total Cost = (Ending Equity) - (Payment x 24) - (Upfront Cash).  For your 'old' car, that's (4,276) - (203.81 * 24) - (1,200) = -1,815.75 For the 'new' car, that's (6,046) - (339.68 * 24) - (2,000) = -4,106.07.  Is one good or bad? Up to you to decide. There are excel formulas like ""CUMPRINC"" that can consolidate some of the table mechanics, but I assumed that if you're here asking you would have gotten stuck running some of those.  Here's the spreadsheet: https://docs.google.com/spreadsheet/ccc?key=0Ah0weE0QX65vdHpCNVpwUzlfYjlTY2VrNllXOS1CWUE#gid=1" "Given the state of the economy, and the potential of a rough near future for us recent grads (i.e. on/off work), I would recommend holding off on large purchases while your life is in flux.  This includes both a NEW car and purchasing a house. My short answer is: you need a reliable vehicle, so purchase a used car, from a major dealer (yes this will add a fairly high premium, but easier financing), that is 4-5 years old, or more.  Barring the major dealer purchase, be sure to get a mechanic to check out a vehicle, many will offer this service for a reasonable payment.  As people point out, cars these days will run for another 100k miles.  You will NOT have to pay anywhere near $27,000 for this vehicle.  You may need to leverage your 10k for a loan if you choose to finance, but it should not be a problem, especially as you seem to imply an established credit history. In addition to this, start saving your money for the house you would like to eventually get.  We have no idea where you live, but, picking rough numbers, assuming a 2 year buy period, 20% down, and a $250,000 home, the down payment alone will require you to save ~$2,000/month starting now. Barring either of these options, max out your money to tax sheltered accounts (your Roth IRA, work 401k, or a regular IRA) asap.  Obviously, do not deplete your emergency fund, if anything, increase it.  10k can be burned through in a heartbeat. Long Answer:  I purchased a brand new car, right out of school, at a reasonable interest rate.  Like you, I can afford this vehicle, however, if someone were to come to me today (3.5 years later) and offer me the opportunity to take it back and purchase a 4-5 year used vehicle, at a 4-5 year used car price, albeit at a much higher interest rate (since I financed), it would be about a 0.02 second decision. I like my car, but, I'd like the differential cash savings between it and a reliable used car more.  $27,000 is also fairly expensive for a new vehicle, there are many, very nice vehicles, for 21-23k.  I still would not consider these priced appropriate to spend your money on them, but they exist.  However, you do very much need a reliable vehicle, and I think you should get one. On the home front, your $400 all inclusive rent is insanely cheap.  Many people spend more than that on property tax and PMI each year, so anyone who throws the ""You're throwing money away!"" line at you is blowing smoke to justify their own home purchase.  Take the money you would have spent on a mortgage, and squirrel it away.  Do your own due diligence and research the home market in your area and decide for yourself if you think home prices have bottomed and will stay there, have further to go, or are going to begin to rise.  That is a decision only you can make for yourself. I'd add a section about getting expenses under control, but you said you could save 50% of your takehome pay.  This is an order of magnitude above the average.  Good job.  Try doing 50% for 4 months, then calculate your actual amount.  Then try to beat it." So hopefully you are not spending the money before you make it.  If you are, you are asking for trouble.  If not the solution is easy. If you use a spreadsheet for tracking have a item in your checking account running total that is simply CC to pay.   Lets say you just got paid, and your balance is like this: You can then do virtual withdrawals for each category In this case you have 70 left to spend.  Whoops the car gets a flat which costs you 5 that you put on the card and you also pay your rent by CC.  Then your spreadsheet should look like this: You still have the 70 left to spend, and when the CC bill comes due you are free to write the check. "They aren't actually. It appears to be a low interest rate, but it doesn't cover their true cost of capital. It is a sales tactic where they are raising the sticker price/principal of the car, which is subsidizing the true cost of the loan, likely 4% or higher. It would be hard to believe that the true cost of a car loan would be less than for a mortgage, as with a mortgage the bank can reclaim an asset that tends to rise in value, compared to a used car, which will have fallen in value. This is one reason why you can generally get a better price with cash, because there is a margin built in, in addition to the fact that with cash they get all their profit today versus a discount of future cash flows from a loan by dealing with a bank or other lending company. So if you could see the entire transaction from the ""inside"", the car company would not actually be making money. The government rate is also so low that it often barely covers inflation, much less operating costs and profit. This is why any time you see ""0% Financing!"", it is generally a sales tactic designed to get your attention. A company cannot actually acquire capital at 0% to lend to you at 0%, because even if the nominal interest rate were 0%, there is an opportunity cost, as you have observed. A portion of the sticker price is covering the real cost, and subsidizing the monthly payment." "In your situation, you probably should not cash in your IRA and 401(k). A good mortgage lender will want to see that you have ""reserves"" -- money that you could fall back on if you hit a very rough patch.  Your current savings and retirement accounts might add up to a suitable reserve. You might want to do something like this instead: By the way, instead of cashing in a 401(k), it is usually better to: This method avoids large tax penalties, and encourages you to rebuild your 401(k).  Unfortunately, your large debt balances might prevent you from getting the PLOC.  But even in the worst case scenario (where you cannot use a PLOC to pay off a 401(k) balloon payment), it postpones the tax hit until after the balloon payment." While this question is old and I generally agree with the answers given I think there's another angle that needs a little illuminating: insurance. If you go with an 84 month loan your car will likely be worth less than the amount owed for substantially all of the entire 84 month loan period; this will be exacerbated if you put zero down and include the taxes and fees in the amount borrowed.  Your lender will require you to carry full comprehensive/collision/liability coverage likely with a low maximum deductible.  While the car is underwater it will probably also be a good idea to carry gap insurance because the last thing you want to do is write a check to your lender to shore up the loan to value deficit if the thing is totaled.  These long term car loans (I've seen as high as 96 months) are a bear when it comes to depreciation and related insurance costs. There is more to this decision than the interest calculation.   Obviously, if you had the cash at the front of this decision presumably you'll have the cash later to pay off the loan at your convenience.  But while the loan is outstanding there are costs beyond interest to consider.