the U.S. National Highway Traffic Safety Administration, which writes and enforce safety standards for motor vehicles and regularly studies the effects of aging on tires, says: “While tire life will ultimately depend on the tires’ service conditions and the environment in which they operate, there are some general guidelines. Some vehicle manufacturers recommend that tires be replaced every six years regardless of use. In addition, a number of tire manufacturers cite 10 years as the maximum service life for tires. Check the owner’s manual for specific recommendations for your vehicle. Remember, it is always wise to err on the side of caution if you suspect your vehicle has tires that are over six years of age.”
Transport Canada does not regulate the age, shelf life or useful life of tires. They do, however, require the date of manufacture to be moulded on the sidewall of every tire. Under the Motor Vehicle Safety Act, Transport Canada develops, maintains and enforces the Canada Motor Vehicle Tire Safety Regulations. These require that all tires have a Tire Identification Number (TIN). This is a string of letters and numbers that are moulded on the sidewall of each tire, and includes the tire date of manufacture.