Most vehicle manufacturers recommend a change of tires every six years. You should check the vehicle's manual to find out when exactly you may need to change tires. However, it is always better to have a mechanic inspect the tires for wear and tear before making the decision. It all depends on the type of vehicle as well as the damage the tires have sustained. For example, construction equipment tires will have a different expiration date to a passenger vehicle. Ask the mechanic to check for tread depth, blisters or bulges and sidewalk cracks. In addition, pay attention when you drive to find out whether the car vibrates or not. If it vibrates that could signal a problem.