New vs. Used Car Loan: How the Total Cost Actually Compares
A used car typically costs less upfront but often carries a higher interest rate than a new car loan, while a new car costs more upfront but usually qualifies for a lower rate — the total cost comparison depends on both the price gap and the rate gap together, not on price or rate alone.
"Buy used to save money" is broadly true on price, but the loan side of the comparison has its own separate trade-off that's easy to overlook.
A worked comparison
A new car at $32,000 with a 6% rate over 5 years: monthly payment around $619, total interest around $5,140. A comparable used version of the same model at $22,000 but with a higher 9% rate (common for used financing) over 5 years: monthly payment around $457, total interest around $5,420.
The used car still has a noticeably lower monthly payment and lower total amount paid overall, despite the higher rate — the $10,000 lower price outweighs the rate gap in this example, though the total interest paid is actually similar between the two because of that higher used-car rate.
Why used car loan rates tend to run higher
Lenders generally view used vehicles as higher risk collateral — they depreciate faster in percentage terms early in the new-car case, but used cars carry more uncertainty about condition and remaining lifespan, which is commonly reflected in a somewhat higher standard rate compared to new-car financing.
Why running the actual numbers beats a rule of thumb
Because both price and rate move in opposite directions between new and used, there's no universal answer — a large price gap can make used cheaper overall even with a meaningfully worse rate, while a small price gap combined with a large rate gap can flip the comparison. Running both specific options through a calculator is the only reliable way to know which wins for a given pair of real offers.