Buying a Used Car? Be Smart About It

doing your homework can save you some headaches down the road

Better Business Bureau

A sign at a used car lot in Quincy, Massachusetts, circa 1984. (Photo by John
A sign at a used car lot in Quincy, Massachusetts, circa 1984. (Photo by John Margolies via Library of Congress)

It’s time to buy a car, and you’ve decided to buy a used (or pre-owned) vehicle rather than a new one. Before you head out to buy your car, do your homework. There are many online resources to check the average retail prices of different makes and models of used cars depending on the year they came out and the number of miles they were driven. Keep these prices in mind as you shop and negotiate. Online resources and publications can also give you information on the reliability records of various models.


When a car is sold “as-is,” there is no warranty, and once you sign papers and drive away the seller has no more responsibility. This makes it especially important to know as much as you can about the condition of the car before you buy it. Don’t expect perfection in a used car, but don’t overlook serious defects. Be alert: Some sellers are adept at masking problems, and a steam-cleaned engine and gleaming paint job are no indication of the quality of the automobile. Check the car in daylight and bring someone along to help you make a thorough inspection.

Exterior: Be sure the body appears even, with no irregular spacing between the body joints. Check for rust, especially at the bottoms of fenders, around lights and bumpers, on splash panels, under doors, and in the wheel wells. Check the tires for uneven wear or signs of brake fluid leakage on the inside. Also, check the spare tire and make sure the correct jack is in the trunk and in working order. Check for paint that does not quite match, gritty surfaces, and paint overspray on chrome – a new paint job could be masking body problems. Look for warning signs of a past accident, like cracks, heat-discolored areas, and loose bumpers. Look for welded seams, which may indicate the car is “rebuilt” from salvaged parts. Look for hairline cracks and tiny holes in the windows. If the vehicle is dirty, have it washed for a better inspection. 

Doors, windows and trunk: Look for a close fit and easy opening and closing of doors. A door that fits unevenly may mean the car was involved in a collision.

Frame and alignment: If you suspect a car’s structural condition, have it checked by a local tire alignment dealer. A car with a bent frame can be dangerous.

Tailpipe: Look for black gummy soot in the tailpipe. This may indicate worn rings or bad valves.

Interior: Check for badly worn carpeting or upholstery, which may be a sign of heavy use. Check the adjustability of the seats and make sure all seat belts work. If the seats have covers, look underneath. Turn on the ignition to check the warning lights, and check the brake pedal. Ask about the working order of the airbags and if they have ever been deployed. Take a sniff! A musty smell inside the car could mean the car was damaged in a flood or that rain leaked in.

Fluids: Pull out the oil dipstick. If it is dark and dirty, the engine may not be well maintained. If the oil is whitish or has white bubbles, it may mean there is water in the system, which can be a sign of major mechanical problems. If the transmission is automatic, check the transmission fluid to see if it is dark or has a burned odor. Check for leaks and stains under the car, on the underside of the engine, and around hoses and valve covers. 

Battery: Look at the sticker on the battery for the guarantee date. You generally need to replace a battery after 25,000 miles.

Electrical system: Check all electrical accessories, such as the lights, wipers, radio, and horn, one at a time. 

Springs and shocks: Push down on the front and rear corners of the car. If the car bounces several times, the shock absorbers are worn.


After going through these visual inspections, take the car for a test drive. If a dealer will not let you go for a drive, you should consider walking away. Here are things to consider on your drive:

• The car should start easily and without excessive noise. Once it has warmed up, listen for engine noises as you drive. Unusual sounds may be signs of trouble. Any noise that sounds strange should be a warning sign.

• Drive on a variety of terrains, such as highways, back roads, and through traffic.

• Does the car idle and accelerate smoothly, or does there seem to be some hesitation? 

• Drive down a straight and level stretch of road while holding the steering wheel lightly. Does the car consistently pull in one direction? Try turning at various speeds. Too much sway or stiffness can mean bad shocks or front-end problems. Turn the wheel all the way from one side to the other. The power steering should feel smooth with little or no squealing.

• Pay attention to how the brakes are working. Does the car pull to the left or right while you are braking? Are the brakes responsive, or does the car seem to require an unusual amount of time to stop?


You also want to pay special attention to the odometer, which tracks the miles the car has been driven. The National Highway Traffic Safety Administration (NHTSA) estimates that consumers lose billions of dollars a year to odometer fraud. Odometer readings can be rolled back, and documents can be forged. Making miles disappear helps increase the car’s value to the seller and can mean increased maintenance and repair costs to the buyer. Here are some things to think about when checking the mileage on a used car:

• Do the math. The average vehicle accumulates about 12,000 miles per year. If the mileage seems excessively high or low in comparison, find out why. 

• Ask the seller if you can see the maintenance records and compare them with the mileage on the odometer itself. 

• Examine the car for telltale signs. Is the wear on the car’s pedals, tires, and seats consistent with the miles on the odometer? A car with fewer than 25,000 miles on the odometer and new tires may be suspicious.

Once you have found a car you are considering buying and you have tested it yourself, have a mechanic check the car thoroughly before you sign anything. You will have to pay for this, but it is crucial, as there could still be problems you did not find.

Ask for a written estimate of the costs to repair any problems the mechanic finds, and use that estimate as a bargaining chip when you make your offer for the car.

For more tips on used-car buying, check out the full article. The Better Business Bureau helps people find businesses, brands and charities they can trust. In 2021, people turned to BBB more than 200 million times for BBB Business Profiles on 6.3 million businesses and Charity Reports on 25,000 charities, all available for free at