Should you pay cash for cars? Yes! Here's the math to prove it.

Quite often, I get emails from readers asking about the “best” way to purchase a particular car that they want. They have their eye on some new model and want me to essentially tell them that it’s okay to purchase it.

I rarely do. Taking out a loan for a car is only a good move if (a) you’re buying your first or your second car and absolutely need one today to commute to work – and even then, you should be buying a used one or (b) you have enough cash to buy the car you want but you’re offered 0% or extremely low financing, making it cost-effective to take out the loan and then sit on your investment (a pretty rare case, but one we found ourselves in recently).

We fully own both of our automobiles and don’t intend to replace either one of them for years. Of course, we’re slowly saving up for their replacements at a reasonable rate, but we’re not paying interest – interest is working in our favor.

Let’s run the math so that you can see, in real dollars, how much is saved by paying cash. You have no cash at all, but you need wheels. What do you do?

Option 1 – Buying New Now
You go to the dealership and take out a $25,000 loan on a new car. That loan is offered to you at 6% for five years, meaning you have a monthly payment of $483.32.

You drive this car for seven years. Each month, you pay $483.32 as a car payment. After five years, you own the car, but you’ve paid out $28,999.20 for the loan – $3,999.20 of that being pure interest. You then start saving $483.32 a month for your next purchase – after two years, your savings account totals $11,715.68 ($11,599.68 in savings, plus $16 in interest).

At the seven year mark, you trade in your used car for $6,000 in trade in and also make an $11,700 down payment on your next $25,000 car. You’re still borrowing $7,300 to buy the car, which means monthly payments of $141.13 over the next five years, totaling $8,467.80 – $1,167.80 of that being pure interest.

At this point, you also need to save $285 a month so that you have $25,000 in cash ready for your next car purchase at the fourteen year mark – seven years after this one. $23,940 of the savings will be cash and the rest will be interest – $1,104.64.

So, after all of this, you wind up paying out $73,006.68 over the course of these fourteen years and find yourself with a new car at the end of it.

Now, let’s look at fourteen years starting in a different fashion.

Option 2 – Buying Used Now
You go to the dealership and take out a $5,000 loan to buy a used car that will work for five years. You make monthly payments of $483.33 each month. For the first year, $430.33 of it goes towards the loan payment, while the other $53 goes into savings. For the remaining four years, the whole $483.33 goes into savings.

At the five year mark, you have just shy of $25,000 saved and the trade-in on your junker puts you over the top. New car time, paid for in cash. You then start saving for your next new car in seven years, saving $285 a month.

At the twelve year mark, you replace that car and keep saving the $285 a month. At the fifteen year mark, you have a three year old car and $10,414.67 in savings.

Over the course of all of this, you’ve actually only shelled out $63,199.80 out of your pocket for these cars.

Comparing These Two Scenarios
Here’s the real take-home message here: simply by buying a low-end used car at first in the second scenario and driving it until the owner could pay cash on a new car (at the five year mark), that owner saves $10,000. In other words, choosing to take out a loan for a new $25,000 car means that $10,000 is simply evaporating out of your wallet.

Remember that from here on out, both scenarios are going to be saving the same amount of money in their savings account to keep up with future car replacements, which essentially means that the money is a car payment.

I like to look at it this way: the owner of the second option is essentially paying himself $2,000 a year to drive a used car instead of a brand new one.

There are a few additional things to point out as well.

First, the insurance costs in the second scenario are lower as well. For those first five years, the person owns a used car which will have lower insurance costs than a new automobile.

Second, considering used cars in your buying decision can save you money. When you run the numbers on your car purchase, always include used cars, particularly ones from model years with a good reputation. Sometimes, those cars can save you significant money over the long haul through insurance savings, plus they allow you to retain some of your cash savings for your next car purchase.

Finally, having the money in the bank puts you in control. If you can buy the car in cash, you’re no longer worrying about your credit history or about whether a bank will offer you a good rate. You have your cash, you find the best deal, and you buy. Simple as that.

I’ll say this much: every time I run the long term numbers with regards to paying cash or taking out a loan for a car, I further reinforce my own plan to never again borrow a dime for a car (unless, as I mention above, I have the money in an investment that offers a better guaranteed return than the interest rate of the car loan).

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