CarCost research library

Make the car decision before the dealership makes it for you.

Plain-language guides that connect the payment to depreciation, financing, trade-in equity, operating costs, and what the car may be worth when you are finished with it.

10 in-depth guides29 cited source pages100% free to read

Decision guides

Start with the comparison you are making.

New vs. used

New vs. used car: how to compare the true cost

Compare a new car with a used car using depreciation, financing, age, repairs, warranty, trade-in equity, and resale value—not payment alone.

7 minute read

Buy vs. lease

Buy vs. lease: compare the full cost, not the payment

Learn how to compare buying and leasing a car using equity, mileage, fees, repeated lease cycles, resale value, and total ownership cost.

7 minute read

Cash vs. 0% APR

0% financing vs. cash: which offer actually costs less?

Compare zero-percent auto financing with paying cash, including rebates, negotiated price, retained cash, investment risk, and monthly cash flow.

6 minute read

Long auto loans

72-, 84-, and 96-month car loans: lower payment, higher risk

See how long car loans affect monthly payments, total interest, negative equity, resale timing, and the true cost of a vehicle.

6 minute read

EV vs. gas

Electric vs. gas car: compare total cost with your local rates

Compare electric and gasoline vehicle costs using purchase price, charging and fuel rates, efficiency, maintenance, insurance, depreciation, and resale value.

7 minute read

Trade-in equity

Trade-in value and negative equity: calculate what really carries over

Understand trade-in equity, loan payoff, rolled-in negative equity, tax treatment, loan-to-value ratio, and the cost of replacing a financed car.

6 minute read

True ownership cost

The true cost of owning a car: what belongs in the calculation

Calculate the full cost of owning a car using depreciation, financing, insurance, fuel, maintenance, taxes, repairs, resale value, and remaining loan balance.

8 minute read

Car affordability

How much car can I afford? Build the budget before the payment

Estimate an affordable car budget using the full monthly ownership cost, upfront cash, loan terms, insurance, maintenance, repairs, and emergency savings.

8 minute read

CPO vs. used

Certified pre-owned vs. used: what does the warranty really cover?

Compare certified pre-owned and ordinary used cars by factory warranty, dealer warranty, service contract, inspection, repair exposure, and price premium.

8 minute read

Calculator comparison

Best car cost calculators compared: which tool fits your decision?

Compare CarCost, Edmunds, Kelley Blue Book, AAA, NerdWallet, Bankrate, Calculator.net, and CarEdge by inputs, ownership costs, time horizon, and best use.

10 minute read

Questions this library answers

Start with the words you would actually ask.

These are reader questions, not promises about rankings. Each cluster leads to a substantive answer and then to the calculator inputs needed to test it.