New on FinoLib · Volume V: Personal Finance
I have added a new article to FinoLib, my finance education website: Auto Loans vs Leasing: How Car Financing Works, part of Volume V: Personal Finance. It is part 1 of a 2-part guide. This page gives you the core of the topic in expert but plain language; the full article goes much deeper.
The idea in plain words
A car loan costs whatever its rate, length, down payment and any old debt rolled into it add up to. The two costliest habits are stretching the loan over many years and bargaining over the monthly payment instead of the car’s price. Get pre-approved by a bank or credit union first, settle the price before talking financing, and choose the shortest term your budget can handle. A lease is really paying for the steepest part of the car’s drop in value.
Key points
■Long terms repay principal slowly: the first payment on a $30,000, 7% loan retires $543.39 of principal on a 48-month term but only $277.78 on an 84-month term, so the long loan stays underwater longer.
■Dealer financing is often marked up above the lender’s “buy rate”; 1.25 points on $30,000 over 72 months adds $1,310.16 of interest.
■Rolled-in negative equity is common and risky: in CFPB data for 2018–2022, 11.6% of loans carried it, and those borrowers were more than twice as likely as buyers with a positive-equity trade-in to face repossession within two years.
■0% financing versus a rebate is a rate comparison: a $3,000 rebate on $30,000 over 60 months beats 0% only if you can borrow below about 4.23%.
A closer look
An auto loan is an amortizing installment loan secured by the car: miss enough payments and the lender can repossess it. Its cost is set by four levers — the APR (driven by credit score, new versus used, and lender), the term, the down payment, and whatever is rolled in from a trade-in. In the second quarter of 2026, commercial banks charged an average 7.14% on 60-month new-car loans and 6.97% on 72-month loans; used-car loans and weaker credit pay more.
A worked example
Worked Example — Compare the Scenarios: 0% Financing or a $3,000 Rebate
Manufacturers often offer a choice of 0% APR or a cash rebate. Illustrative assumptions: $30,000 to pay for the car, 60 months, a $3,000 rebate, a credit-union rate of 7.0%, and savings that earn 4.0%. With 0%, the payment is $30,000 ÷ 60 = $500.00. With the rebate, $27,000 at 7% is $27,000 × 0.0058333 ÷ [1 − 1.0058333^−60] = $534.63. To compare cash today with payments spread over five years, discount each stream at the 4% your savings would have earned: present value = payment × [1 − (1 + 0.04 ÷ 12)^−60] ÷ (0.04 ÷ 12). Choice Monthly payment Total paid Present value at 4% A. 0% APR, 60 months $500.00 $30,000.00 $27,149.53 B.
Under the hood
Under the Hood: Why the Dealer’s Rate Can Differ From the Lender’s
Most dealer financing is indirect: the dealer sends your application to lenders, each lender sets a risk-based buy rate, and the dealer may write the contract at a higher rate and be paid part of the difference. When the CFPB and the Justice Department settled with Honda’s finance arm in July 2015, Honda had let dealers mark rates up by as much as 2.25 percentage points on contracts of five years or less (2 points on longer ones), and it agreed to cap markups at 1.25 points (1 point on longer terms) (CFPB, Jul 14, 2015). The cost is easy to miss because it hides in the payment.
Why It Matters: What the Lending Data Show
Auto debt is the second-largest category of household debt after mortgages: $1.71 trillion at the end of June 2026, against $1.65 trillion of student loans (New York Fed, Aug 11, 2026). The best public evidence on how buyers get into trouble comes from the CFPB’s Auto Finance Data Pilot, which studied loans made in 2018–2022 (CFPB, June 2024).
Edge Cases: When the Standard Answer Changes
The standard advice assumes one borrower, a personal car and payments that keep coming. These situations change it. Situation What changes Why Number or rule A co-signer on the loan The co-signer owes the whole debt, not a share, and the account appears on both credit files Each signer is liable on the contract; in many states the lender may collect from the co-signer without first pursuing the borrower FTC Notice to Cosigner: “you may have to pay up to…
What the full article covers
The full article includes worked examples, a look under the hood at the mechanics, a recap, a reveal-on-click quiz and the official sources behind every figure.
Volume V: Personal Finance
Read the full article on FinoLib
The complete article, Auto Loans vs Leasing: How Car Financing Works, with every worked example, diagram, quiz and source, is free to read in Volume V, Personal Finance on finolib.com.
Explore the Finance Education Series: Vol. II — Capital Markets · Vol. I — Global Economy · Vol. III — Finance Encyclopedia · Vol. IV — Finance Careers · Vol. V — Personal Finance