(BPT) - When shopping for a new or used car, the test drive is an essential part of the process. While the test drive may be exciting, experts advise car shoppers keep emotions in check and evaluate the car in its entirety to make a good purchase decision.

"A test drive shouldn't be just a joyride," says Joe Wiesenfelder, executive editor at Cars.com, who test drives more than 150 cars each year. "This is your chance to size up the car when it's stationary, and to drive it like you plan to every day and make sure it's the right car for you."

When test driving a used car:

* Check for any unusual or bad smells, sounds and sights.
* Write down anything that seems damaged or suspicious; refer to this before you make that big purchase.
* Bring a second person along to act as a second set of eyes and ears.
* Bring the car to a trained mechanic to inspect the vehicle, detect overlooked faults and predict future maintenance costs. If the seller doesn't allow you to take it to a mechanic, walk away.

For both new and used vehicle test drives:

* Explore the car fully before you drive; you can't concentrate on everything at once.
* Make sure you are comfortable in the car.
* Check the visibility in all directions.
* Figure out whether this car fits your lifestyle. For example, can you install that child seat without trouble? Will your bike fit in the trunk? Is there enough room in the cargo area for a dog kennel?
* Judge if the car you're testing has the right options; dealers may have more of the same model with different options, or you may consider ordering a car to suit your preferences.
* Come prepared ahead of time. Do some research on the automaker's website if you know what kind of car you want, as well as on unbiased third party sites like Cars.com.
* If you are not allowed to test drive the vehicle, walk away and consider a different seller.

"Really drive it," says Wiesenfelder. "Take it to common places you drive. Will it fit in your garage or parking spot? Are you willing to drive this car to work every day? Can you maneuver it in tight quarters with ease? These are all questions to answer before and during your test drive."

While emotions can be the biggest influencer on a test drive, experts recommend that you be prepared to walk away if you are not completely satisfied. "There are plenty of other new and used cars in the market," says Wiesenfelder.