This is an obvious one, but you really do need to know what the size of your factory tire is, and what size tire the wheel can take. Vehicle manufacturers design suspension and handling components with the factory wheel and tire size in mind. Changing the size of the tire can affect how your vehicle performs and handles [source: Motor Trend]. If you're looking to add a larger size tire, take a look at your car's owner's manual first to see the manufacturer specifications and recommendations. If you're making a drastic change in tire size, consult a tire expert before you do anything to find out how your vehicle may be affected. And remember: What looks good in the showroom may not be the best for your car's on-road handling, suspension components or turning radius.
On the next page we'll review speed ratings for tires.