There are many reasons why a person may purchase a used vehicle. No matter what the reason to purchase may be, we all ultimately want to purchase a vehicle that is safe, comfortable, and reliable. Therefore, a test drive is one of the most important steps in determining whether or not to purchase a used vehicle.
You can tell a lot about a vehicle during a test drive, especially if the drive consists of varied speeds and road conditions, left and right turns, acceleration and deceleration, multiple braking situations, a predetermined list of checkpoints, and an experienced and alert driver.
The test drive begins the moment you sit in the vehicle and become familiar with the features and locations of the accessories. Before starting the vehicle, turn the key or set the ignition or start button to the accessory position, which is the last position before the engine starts. All the dash warning lights, including the check engine light, should illuminate. If they do not, there may be a problem. It could be as minor as a burned-out bulb, or as serious as someone having tampered with the display to disguise a problem.
Upon first starting the engine, listen for any noises such as tapping, ticking, knocking, squealing, or any other unusual noises. After securing your seatbelt, inspect the instrument panel to see if any warning lights stay on while the engine is running. This is also a good time to see if the gauges are working, honk the horn, and quickly familiarize yourself with the accessories.
Turn on the heater and air-conditioning blower fan and test it on all speeds. Test the modes to ensure air blows where it is supposed to, and at an acceptable noise level. Turn the windshield wipers on, including the rear if equipped, and test them on every speed while spraying washer fluid on the glass. Make sure the wiper blades clean the glass and do not chatter, streak, or miss sections of the windshield while wiping.
Prior to shifting the vehicle into gear, turn the steering wheel from side to side and listen for unusual noises. Make sure the steering does not bind or stick. Pump the brake pedal a few times then press hard with your foot. The brake pedal should be firm, not soft or spongy. If the pedal slowly sinks all the way to the floor, there may be a leak in the brake system, or the master cylinder or brake booster may be faulty.
Apply the parking brake and carefully shift the vehicle into gear. The parking brake should hold the vehicle from moving, and the parking brake engagement light on the dash should come on. Make sure your foot is on the brake pedal and release the parking brake. With your foot firmly on the brake, shift from drive to reverse and vice versa. Clunking noises when shifting into gears could indicate worn or broken engine or transmission mounts, a bad universal (U) joint, a faulty constant velocity (CV) joint, or differential wear.
Now you are ready to drive the vehicle. If the vehicle has an automatic transmission, the transmission should engage immediately and, as you drive, should shift through each gear smoothly, firmly, and quickly. If the vehicle is a manual transmission, there should be no grinding or groaning sound of any kind from the transmission when you select gears, and the clutch engagement should not be too low or too high.
As you begin the test drive, make sure the steering wheel is centered when driving straight. The steering wheel should not shake or vibrate while driving at any speed. Vibration in the steering wheel while driving can mean anything from an unbalanced tire to a loose steering component. If the steering wheel shakes, or if you feel a rhythmic pulsation in the brake pedal while braking, this could indicate warped brake rotors or a sticking brake caliper. Vehicles with antilock brakes (ABS) will have a slight pulsating action in the pedal when the brake is applied with great force, or while driving over slippery surfaces. Pulsating under such conditions is a normal function of an ABS system.
With your hands loosely on the wheel, you can determine if the vehicle pulls to the left or right when braking. It should glide to a stop in a straight line or pull ever-so-slightly to the right because of the crown of the road. The vehicle should never pull to the left.
When safe to do so, take your hands off the wheel while driving on a flat surface to determine if the vehicle pulls in one direction when the brake has not been applied. Do this a couple of times on different flat road surfaces. This test could indicate potential front-end alignment or tire issues.
Drive the vehicle on a bumpy or uneven road. If you’re unable to do so, a parking lot with speed bumps should work just fine. Pay attention to how the vehicle responds while driving over the bumps. Listen for any rattles in the vehicle, and for any strange noises coming from the suspension.
Unless you're evaluating the sound system, leave it off during the test drive. If you’re running the heater or air conditioner, turn those systems off after testing them, but leave the windows up. This will allow you to listen to the vehicle operate. Though it may be difficult even for some seasoned technicians, do your best to separate normal noises from those that may indicate a problem with the vehicle.
Continue to use all your senses throughout the test drive. If the vehicle is four-wheel drive, make sure it works. Test the heater and air conditioning systems while you are driving. How does the vehicle sound and feel when you accelerate, turn, or brake? Are there any unexplained noises when you accelerate or decelerate? How does it feel at higher speeds and lower speeds? While driving, keep an eye on the instrument panel so you can identify any gauges that aren’t operating properly, or any warning lights that come on.
Things you feel in your seat are often associated with the rear end of the vehicle, while things you feel with your fingers on the steering wheel tend to come from the front suspension, steering, engine, brakes, or tires.
A thorough pre-purchase inspection should always include a test drive. Most buyers know a test drive is crucial in finding the best value in a used vehicle, but few know how to perform an examination that will separate the good from the mediocre. Your best bet is to have a trusted, impartial ASE certified technician perform a test drive as part of a thorough used vehicle evaluation. This will give you the best chance of separating clunkers from keepers, and will help you find a safe, comfortable, and reliable used vehicle.