Cooper Tire Recommendation
The useful life of a tire is a function of service and storage conditions. For each individual tire, this service life is determined by many elements such as temperature, storage conditions, and conditions of use (e.g., load, speed, inflation pressure, impacts and road hazard damage) to which a tire is subjected throughout its life. Since service and storage conditions vary widely, accurately predicting the service life of any specific tire based on calendar age is not possible.
Cooper Tire is not aware of scientific or technical data that establishes or identifies a specific minimum or maximum service life for passenger and light truck tires. However, Cooper recognizes a consumer benefit from a more uniform, global industry-wide approach to the tire service life issue. Accordingly, Cooper recommends that all tires, including full-size spares, that are 10 or more years from their date of manufacture, be replaced with new tires. Tires 10 or more years old should be replaced even if the tires appear to be undamaged and have not reached their tread wear limits. Most tires will need replacement before 10 years due to service conditions. This may be necessary even if the tire has not yet reached its tread wear limits.
Under no circumstances should a “maximum” service life recommendation for a tire be considered as an “expected” service life. Tires must be removed from service for several reasons, including tread worn down to minimum depth, signs of damage (cuts, cracks,bulges, impact damage, vibration, etc.) or signs of abuse (under inflation, overloading,
improper repair, etc.).
In some cases a vehicle manufacturer may make a recommendation for tire replacement earlier than 10 years for their products based upon their understanding of the specific vehicle characteristics and application. If so, the consumer should follow those vehicle manufacturer’s specific recommendations for their vehicle.
A tire’s date of manufacture is located on each tire. A consumer can determine the date of manufacture by examining the series of letters and numbers called the Tire Identification Number (TIN) which follow the letters “DOT” on the tire sidewall. For tires manufactured after the year 1999, the last four numbers of the TIN identify the week and year in which the tire was manufactured. The first two numbers identify the week and the last two numbers identify the year of manufacture. Thus, a TIN ending
with “3005” indicates that the tire was made during the 30th week of 2005 and would appear as DOTXXXXXXX3005 on the sidewall of the tire.
For tires manufactured prior to 2000, three numbers instead of four indicate the date of manufacture. The first two numbers reflect the week and the last digit reflects the year of manufacture. Thus, a TIN ending in 308 indicates that the tire was made in the 30th week of 1998 (or possibly 1988) and would appear as DOTXXXXXXX308 on the sidewall of the tire.
Consumers have the primary responsibility for the regular care and maintenance of their tires. Tires should be inspected at least once per month. The regular inspection should focus on proper inflation pressure, tread wear and tire/wheel damage as detailed below. Having tread depth above the legal limit does not determine the service life of a tire. Tires must be properly maintained and routinely inspected for continued safe and proper use — even when tread depth remains. Tires may need to be taken out of service even
when tread depth above the legal limit remains. Regular inspection becomes particularly important the longer a tire remains in use. This monthly inspection should be supplemented by periodic rotation, balancing and alignment services. Inspection should occur whether or not the vehicle is equipped with a tire pressure monitoring system.
Tires should always be stored in a dry, cool, well-ventilated place. Avoid storing tires in areas that are exposed to wetness, petroleum or petroleum-based products, extreme temperatures, direct sunlight, and/or other sources of ozone, such as electric motors. Storage areas should also be clean and free of grease, gasoline or any corrosive chemicals which can deteriorate rubber.
If a vehicle is fitted with a matching full-size spare tire the consumer should follow the vehicle manufacturer’s recommendation for rotating the spare tire. In the absence of a manufacturer’s recommendation, Cooper recommends a five tire rotation, including the spare tire. When any spare tire is placed into service, its inflation pressure must be checked.
Besides monthly inspection of their tires’ visual condition, consumers must also be aware of any change in dynamic performance such as increased air loss, noise or vibration. These conditions could be caused by internal damage to the tire and may require that the tire be removed from service immediately to prevent a tire disablement. Cooper recommends that consumers consult a tire service professional if any dynamic performance issues are noted.