Tires 101: What you need to know to replace your tires

When it comes time to replace the tires that came on your car, it is important to buy the right ones.

"Today, you can have a lot of different aspects of the tire that you really don't know about," said Rick Brennan, executive director of marketing at Falken Tire's U.S. headquarters in Rancho Cucamonga.

It's not necessarily the brand, but the exact size than can be a bit confusing.

Decades ago, there were only about a dozen sizes of tires, as tire technology was pretty basic. Now, hundreds of sizes are available.

A tire might be specified to work with a particular car and suspension system and vice versa.

"It's really important for the car, because it was designed for that type of performance level for contact area and keeping things consistent so it always feels the same," Brennan said.

Also important is the speed rating. Tires are certified by what kind of high speeds can be sustained with them.

Higher performance cars come with tires rated for very high speeds, but even conventional passenger cars these days are often equipped at the factory with speed-rated tires.

Most people would assume that a tire rated to do sustained speeds of up to 149 miles per hour is overkill because they're never going to drive close to that fast. But it's not just about the actual speed the tire can safely do.

"We do things to the tire to make sure it keeps its shape at that high speed. But it works at 80 miles per hour, the same way it does at 130," Brennan said.

That's why you don't want to skimp on tire ratings. Legally, a tire installer can't downgrade the tires to a lower speed rating. A reputable tire dealer will only install comparable or upgraded tires. It's for safety, and to keep your car handling the way it was designed to.

Although a lot to know, considering that you only have four small pieces of rubber between you and the pavement, choosing the right tires is very important.