How do they look?
Are your tires cracked or lumpy? Do they still look like that after filling them with air? They might have to go. Sidewall cracks may indicate an air leak in your tires. Any tire blisters or bulgers could be weak spots, which can ultimately blow the tire up.
How is the tread?
Tire tread depth is very important. It affects a vehicle’s ability to break and stop on a wet surface. If the weather is wet and your ties have a shallow tread, you’re risking hydroplaning. Tires that are 4/32″ or less, are to be replaced.
Is the wear pattern even?
Look at your tires. Do they have an even wear pattern? If one side or one area seems to be more worn out than the others, it might need replacement. To avoid such problems in the future, rotate your tires once every 6,000 miles so they wear unevenly.
How old are they?
A tire’s lifespan is about 6 years, but they usually wear out sooner than that, depending on how often and how far you drive. Factor your tires’ actual age with any signs of your visible aging to determine if they should be replaced.
Do they vibrate
Do your tires vibrate for a reason that isn’t a bumpy road? Does the vibration become more violent when you speed up? This might indicate that your tire is unbalanced or misaligned. Either that or you need to replace your shock absorbers.