Tires should generally be replaced every 6 years regardless of mileage, as the rubber compounds degrade over time, leading to cracking, reduced flexibility, and increased risk of blowouts

. Even if tires appear unused, aging can compromise their safety. It is also recommended never to use tires older than 10 years

. Another key factor for replacement is tread depth. The minimum safe tread depth is 2/32 inches; once the tread wears down to this level, tires should be replaced to maintain traction and safe braking

. The penny test is a simple way to check tread depth: if Lincoln’s head is fully visible when inserted into the tread, the tire needs replacing

. Other considerations include:

• Tires exposed to extreme temperatures, rough roads, or long periods of disuse may need replacing sooner than 6 years

• Tires should be inspected monthly or before long trips for damage or abnormal wear

• Uneven wear due to improper inflation or lack of rotation can shorten tire life; rotating tires every 5,000 to 8,000 miles helps prolong their lifespan

• On average, tires last between 36,000 to 75,000 miles depending on driving habits and conditions

In summary, replace tires when they are over 6 years old, when tread depth falls below 2/32 inches, or if there is visible damage or performance issues. Regular inspections and maintenance can help determine the optimal replacement time for safety and performance.