Also check out the Wheel Category Matrix

Before purchasing new tires, you should decide (1) what you want most – long tread wear or sport-style traction, (2) how you plan to drive (touring or aggressively), and (3) the look you want. Once you’ve decided, click on a tire category in the matrix to learn about the attributes of those tires. Key points to keep in mind:

• Never mix speed ratings

• Never mix tire types (radial and non-radial)

• Lower-speed-rated tires reduce the safe speed of your car

• Tire pairs (on same axle) need to match closely in terms of type and tread wear

• Changing tire size will likely result in getting a new set of wheels – this is tire size and manufacturer specific, so check around first.

Tire dealers are an excellent source of information on safety and proper sizing. Once you know what you want (see above and the matrix information), dealers can help you select the best tire and wheel solution for you. Be sure to first review their warranty policies, hazard insurance, and rebates.

Learn about Tire Sizing or Plus Sizing Tires