The Real Cost of a 72-Month Car Loan
The lower payment is real. So is the extra interest and the longer stretch of owing more than the car is worth.
The average new-car loan term in the US has crept upward for over a decade, and 72-month (six-year) terms are now common, with 84-month terms increasingly offered. The appeal is straightforward: stretching the same loan amount over more months lowers the monthly payment, which is what most buyers are actually budgeting against at the dealership. The two costs that lower payment quietly trades away — extra total interest, and a longer window of owing more than the car is worth — are easy to underweight in the moment, because neither shows up on the sticker next to the payment.
The interest cost, in numbers
Take a $30,000 loan at 6.5% APR. Over 60 months, the payment is about $587/month, and total interest paid over the life of the loan is roughly $5,220. Stretch the identical loan to 72 months at the same rate, and the payment drops to about $505/month — a real, noticeable $82/month improvement — but total interest rises to roughly $6,360. You pay about $1,140 more in interest for a payment that is $82/month lower. Stretch to 84 months and the gap widens further: payment near $450/month, but total interest closer to $7,800 — roughly $2,600 more than the 60-month loan.
Run your own numbers on the Loan Payment Calculator with a few different terms side by side — the pattern holds across loan amounts and rates: every additional year stretched onto the term buys a smaller and smaller reduction in monthly payment, for a larger and larger increase in total interest paid.
The quieter cost: negative equity
Cars depreciate fastest in the first two to three years of ownership — commonly 20% or more in year one alone for a new vehicle. A 72- or 84-month loan amortizes slowly in the early months (most of each payment is interest, not principal, in the first year or two of any amortizing loan), while the car's value is falling fastest during that exact window. The result is a longer stretch of time where the loan balance exceeds the car's resale value — being "underwater" or "upside-down."
This matters most at the point of sale or trade-in, and especially after an accident. If the car is totaled while underwater, a standard insurance payout covers the car's actual cash value, not the remaining loan balance — the difference comes out of pocket unless you specifically carry gap insurance. It also matters if your circumstances change and you need to sell or trade in the car before the loan term ends: a longer, slower-amortizing loan means a longer window where doing so requires bringing cash to the table rather than walking away even.
When a longer term is still the reasonable choice
None of this makes a 72-month loan a mistake in every case. If the lower payment is what makes a necessary, reliable vehicle affordable at all — as opposed to a preference for a more expensive vehicle than a shorter term would justify — the calculation changes. The problem case is using the longer term to afford a more expensive car at the same payment you'd have accepted on a shorter loan for a cheaper one; that's where the extra interest and the extended underwater period are pure cost with no offsetting benefit.
A reasonable rule of thumb: pick the term first, based on what you can responsibly commit to (many advisors suggest not exceeding 60 months for this reason), and then shop within the vehicle price that term supports — rather than picking a vehicle price first and stretching the term to make the payment fit.
Related tools
- Loan Payment Calculator — compare terms side by side on the same loan amount
- Compound Interest Calculator — see what the extra interest could be worth if invested instead