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Should you Take the Rebate or Low Interest Finance Deal?

When low advertised interest rates yield a higher cost of borrowing than traditional bank rates.

In most cases dealers use their manufacturer's financial institutions to finance new cars. General Motors has set up GMAC and Chrysler has formed Chrysler Credit, for example.

Rebate Vs Low Interest Loan:

Vehicle Sales Price:
Sales Tax (by state): %
+ $
Title and Registration:
+ $
Cash Down Payment:
- $
My Trade-In Value:
- $
Amount Owed on My Trade-In:
+ $
Market Finance Rate (APR): %
Loan Term (months):
Decision: Low APR
Low APR (True Market Value finance rate will be displayed if no Low APR incentive available): %
Total Loan Amount:
Monthly Payment Using Special Dealer Rate:
Decision: Customer Cash Back
Customer Cash Rebate: $
Total Loan Amount:
Monthly Payment Using Special Dealer Rate:

These institutions are responsible for generating all the low interest ads you see on television or in the newspaper. You have probably seen these ads; they usually state interest rates such as 0 percent or 0.9 percent for 48 months on select vehicles, and then have a lot of small print you cannot read at the end of the ad.

If you can read the small print, you usually see a low rate advertised or cash back. For example, you will see 0.0% or $1500 cash back on all select models. This means that you have two choices. You can opt to go with the low interest rate, or you will get a discount or cash back of $1500 if you finance yourself or pay cash. In any case, you do not get both! This section covers this type of financing and reveals the pros and cons of using manufacturer financing.

When to use manufacturer-financing rates and when to use your bank.

Let's assume that you are buying a car that offers 2.8 percent financing or $2,000 cash back. The vehicle price is $20,000 and in this example there is NO tax.

Because there is $2,000 cash back, you will have to add that to the total loan. For example:

$20,000 + $2,000 = $22,000
$22,000 financed for 48 months at 2.8 percent gives you a payment of $485.01 per month.

If you went to your bank and financed the car, you would save the $2,000 on the selling price but your interest rate is high - let's assume 7 percent. In this case, you would have:

$20,000 financed for 48 months at 7 percent gives you a payment of $478.92. Notice it is only a $6.97 per month difference! (7 percent is cheaper!)
How can a 2.8 percent interest loan and a 7.0 percent interest loan be only $6.97 per month difference in payment?AND why does 7 percent offer a cheaper loan payment?

Let's look at the cost of borrowing to determine what is happening.

On the 7.0 percent loan and the amount financed was $20,000 and the total interest you would pay over 48 months is: $2,988.16.

On the 2.8 percent loan the interest, you would pay is $1,280.48. However, you would pay $2,000 more for the car. Your real cost of borrowing is then $3,280.48. (That's $2,000 + $1,280.48= $3,280.48)

The real difference is $3,280.48 (The 2.8% cost of borrowing) - $2,988.16 (the 7% cost of borrowing) = $292.32. That is it! 2.8 percent has a cost of borrowing of $292.32 higher than the 7 percent loan!

So how do you combat this situation to get the best loan?
You have to determine the break-even rate of the loan and shop that amount. The break-even rate is the normal interest rate that matches your payment on the low financing. For example, the following two loans have completely different interest rates yet their payment is the same.

Loan One: 2.8% Financing
$20,000 - car price plus
$2000 Rebate (Total loan amount = $22,000)
48-month term
$485.01 per month payment

Loan two: 7.65% Financing
$20,000 - car price
48-month term
$485.01 per month payment
Notice that the payment of $485.01 per month is the same at 2.8% and 7.65% (Because of the $,2000 increase in the price of car at 2.8%, the cost of borrowing and the payment are the same.)

Your break-even Interest rate is 7.65% - the interest rate that provides the same payment as the low interest manufacturer's loan. By knowing the true cost of borrowing, you can determine if your bank or any other lending institution can give you better terms. For example, if your bank is willing to give you a lower rate than 7.65%, then your payment for the car will go down and you will save money. If they offer you 7.3%, you will get better terms and savings than the manufacturer's 2.8%.
An easy way to determine your break-even rate of interest:

Step one is to determine the exact payment of a car loan at the manufacturer's low interest special. To do this, you need to get the exact price on the road with all your taxes minus any down payment. Take the lump sum of the loan and figure out the payment at the special interest rate using an advanced loan calculator. This gives you payment one. (You can use an advanced Low APR Interest VS Rebate calculator above to make this easy.)

Next, you need to determine the price on the road of a vehicle that has no rebates or add-ons to the price (in other words, a cash price). With this amount, you need to work backwards to figure out what interest rate would give you the same payment as the low interest rate payment the dealer is using. You need to roll back your payment in the calculator to interest.

For example, the payment in the example above is $$485.01 per month at 2.8%. To figure out the interest rate that would give you the same payment on the cash price, you would enter the on the road cash price into the calculator and the payment of $485.01 and ask it to roll back by interest (to calculate the interest). The interest you would get is 7.65%. - the break-even interest. Now contact your bank or lending institution and see if they will beat that 7.65% rate. If they do, you will save money! (Note that the low rates used by the dealers are fixed rates that do not fluctuate with interest rates. Make sure you are getting a quote on a fixed rate of interest and not a variable rate that floats up and down as interest rates change. You have to compare apples to apples.)