A flat tire is always a bummer, but having a spare tire can help get you back on the road quickly… If you have a spare tire… and if you do have one, it might not be ready or safe to use when needed. Consumer Reports reveals what you need to know before a tire emergency strikes.

Consumer Reports says safety comes first in the event that you do get a flat tire; you should pull off the road as far as you can in a safe area.

Next, you'll want to have a space-saver spare tire… lovingly called the donut. It long ago replaced the full-sized spare in most passenger cars. With any luck, you might go years without needing to use one, but it should not be forgotten. 

Your spare tire expires just like your other four tires. You heard right. Spare tires expire. The last two digits of the DOT number on the sidewall of the donut tire indicate the year the tire was manufactured. If it’s older than ten years, replace it.

And, of course, a spare tire only works if it’s properly inflated. Check your spare tire’s pressure and condition anytime you check the pressure on your other tires and top off as needed.

Sixty percent of new cars don’t have a spare tire. Manufacturers are removing it to lower production costs and reduce weight for fuel economy, so don't assume you have one.

Instead, you’ll likely get an air compressor or a can of tire sealant that is supposed to patch a damaged tire and get you to a shop where it can be repaired or replaced. 

Some cars, mostly luxury models, come with run-flat tires that allow you to continue driving for a set distance, usually 50 miles at modest speeds—enough to get you home or to a service center for a replacement. You shouldn't drive around on these tires or a patched tire because it's not a permanent fix.

Another important tip from CR – no matter what flat tire solution your car has, learn how to use it before you need it because you may need to use it in the rain, dark, or other challenging circumstances.