Repair or replace your car

The question is not whether the repair costs more than the car is worth; it is which option gives you the lower cost per year of reliable transport. A large repair on a sound car can be the cheapest motoring available, and a small repair on a car with several more failures waiting can be the most expensive.

The comparison to run

Write down the repair quote, the car's current value and the cost of the replacement you would buy. Then estimate how many more years the repaired car will reliably serve and how many the replacement will serve. Divide each total cost by its years of service to get a cost per year, and compare those two numbers.

Include the costs that change with the decision. A replacement carries sales tax, registration, insurance changes and the depreciation of a newer vehicle. A repair carries the risk of a second failure, which is why the reliability estimate matters.

The method is deliberately simple because the honest inputs are uncertain. What it prevents is the common error of comparing a repair quote with a car's trade-in value, which are not the same kind of number and do not answer the question.

When repair is usually right

Repair is usually right when the car is otherwise sound, the repair addresses a known failure, and the car has several years of useful life left. A transmission or an engine repair on a car with good body and a known service history can be far cheaper per year than replacing it.

Repair is also right when the alternative is a car payment you cannot comfortably carry. A loan on a replacement vehicle is a multi-year commitment, while a repair is a one-time cost, and the comparison should include the financing cost of the replacement.

Repair is right when the failure is isolated. A single alternator, water pump or wheel bearing is a component, not a verdict on the car. Ask the mechanic whether the failure is typical for the mileage or a sign of wider wear.

When replacement is usually right

Replacement is usually right when the repair is one of several failures in a short period, when the body or frame is compromised, or when the repair cost is a large share of the replacement cost and the car has little life left. At that point the repair is funding a car that will need another repair soon.

Replacement is also right when safety has deteriorated. Structural rust, failed brakes that keep failing, or airbags that no longer work are not maintenance items. Safety should end the comparison rather than enter it.

If you do replace, compare the total cost of ownership of the replacement, not just the purchase price. Fuel, insurance, maintenance and depreciation vary widely between models, and the total-cost-of-ownership calculator on this site is built for exactly that comparison.

Source: Internal Revenue Service, standard mileage rates, published in cents per mile. The rate is the IRS estimate of the cost of operating a vehicle, not a repair quote.

Published running-cost context

The IRS standard mileage rate is the government's own estimate of the cost of operating a vehicle for business, and it is a useful benchmark for the running cost of the car you already own. The Bureau of Labor Statistics publishes average fuel prices, which move the comparison when fuel is expensive.

Financing a repair

The example below uses the Federal Reserve H.15 bank prime loan rate and a standard amortising schedule. It is arithmetic from a published rate, not a quote, and it shows what borrowing to repair adds to the decision.

Worked example, with the assumption stated: $4,000 borrowed at the Federal Reserve H.15 bank prime loan rate of 6.75% (published 2026-09-16) repaid over 24 months on a standard amortising schedule. That gives a monthly payment of $178.64, total interest of $287.30 and a total repayment of $4,287.30. This is arithmetic from a published rate, not a quote: a real APR includes fees and is set by the lender from your credit, so your figures will differ. If the repair buys several years of service, the interest is small relative to the cost of a replacement vehicle. If it buys six months, the arithmetic reverses.

Compare the total of payments with the monthly cost of a replacement car loan. The two numbers are the decision, and both should be compared over the same period.

Getting the diagnosis right

A repair-or-replace decision is only as good as the diagnosis. Ask for a written estimate that states the failure, the recommended repair and the consequence of deferring it. A second opinion on a large repair is free or low cost and frequently changes the recommendation.

Ask the mechanic what else is likely to fail in the next year given the mileage and the service history. That question turns a single repair quote into a forecast, which is what the comparison actually needs.

If you decide to repair, get the warranty in writing and keep the invoice. If you decide to replace, get a written offer for the car and compare it with a private sale, because the difference can exceed the cost of the repair you were trying to avoid.

One more number belongs in the comparison: the cost of not having a car while the decision is made. A rental car during a long repair, or a missed shift, is a real cost that a spreadsheet of repair quotes does not capture. If the car is essential to your income, that urgency argues for whichever option restores reliable transport fastest, even if it is not the cheapest on paper.

Where these figures come from

Related pages

• Auto repair costs by state and province
• How to pay for car repairs
• Total cost of ownership calculator
• Loan payment calculator

Frequently asked questions