Shelf life of tires: what is it and how to extend their service life
Service life of tyres is a period of time when the manufacturing company guarantees compliance of the tyre characteristics with the declared values. During this period, tyres can be used without any restrictions and concerns for driving safety.
What affects the service life of tyres
The age of the rubber can be determined by the part of the DOT code indicating the date of production, which is marked on all tyres. It is commonly a four-digit number:
- The first 2 digits are the week of production (counted from the beginning of the year).
- The last 2 digits are the year of production (the last 2 digits of the year).
For example, part of 1013 DOT code means that the tyres were produced at week 10 in 2013.
Most manufacturers recommend buying new tyres after 6-7 years of operation. Even if the tread is in normal condition, by this time rubber loses most of its physical and chemical properties, which directly affects driving safety.
Shelf life may vary depending on the manufacturer and speed limit:
- ZR. Tyres designed for driving 240 km/h and more. Service life is 6 years.
- H. The upper speed limit is 210 km/h, and the service life is up to 5 years.
- S. Permissible speed is up to 180 km/h, service life is 4-5 years.
If, by the end of the season, you find that service life of the tyres has come to an end, then you need to purchase a new tyre set by the next season. In case of winter tyres, it is worth planning a purchase for the summer, since the cost of tyres is usually somewhat lower in the off-season. You can also save money at the end of the season, when manufacturers get rid of unsold stock.
Tyre life depends on the following factors:
- storage conditions;
- proper maintenance;
- operating conditions;
- condition of road;
- driving habits.
To increase the service life of car tyres, the storage conditions shall be observed. Many car owners neglect this rule, which can lead to tyre failure and reduction of operation time. Tyres with rims and without rims are stored differently:
- Tyres with rims. Storage only in horizontal or suspended state. Do not place tyres upright.
- Tyres without rims. Such tyres, on the contrary, cannot be suspended and stacked on top of each other. They are allowed to be arranged only vertically, subject to turning over every month.
Important tyre storage tips:
- After dismounting winter or summer tyres, it is necessary to check their condition to exclude any damage.
- Before stacking tyres for storage, check the pressure and inflate them to the required level by adding 0.5 bar to each one.
- Mark the rare and front tyres accordingly, for example, like this: FL – front left, FR – front right, RL – rear left, RR – rear right. For marking, you can use chalk or some stickers.
- Choose a dry and clean place with no direct sunlight for storage.
To increase the service life of tyres, regularly check their pressure. The procedure should be carried out every 2-3 weeks. Correct pressure is very important as it ensures uniform tread wear. 10% decrease in pressure leads to a decrease in service life by 10-15%. Tyre wear increases as well with increased pressure.
Proper Maintenance of Tyres Includes Additionally:
- Check of wheel balancing every 10-15 thousand km, including every case of repair.
- Annual check of wheel alignment angle.
- Regular cleaning of tyres from dirt.
- Use of special care products for tyres: colour restorer, conditioner, etc.
Compliance with Operating Conditions
A particular influence on the service life of tyres has driving style. With a calm driving style, tyres wear out slower. It is very important how the car owner applies the brake. If abruptly, then the tyres wear out faster. The same happens with an abrupt change of direction. Such manoeuvres are appropriate only on testing tracks or roads with special road surface.
To increase service life of tyres, one should:
- Run them the first 500 km without manoeuvres, abrupt movements and braking.
- Avoid close driving to curbs, which could cause damage to the side of the tyre.
- Avoid overloading the vehicle if possible.
Other Important Factors
When choosing new tyres, it is necessary to take into account the dimensions of the rims, the model and brand of the car, and the driving style. Climatic conditions are equally important. For example, for regions with a large amount of rainfall, one should choose tyres that drain water well.
A few more important factors affecting the service life of tyres:
- Condition of the road. Pits, potholes and other defects of the road surface have a significant impact on the car. The more often the car runs into them, the less the tyres will last.
- Complete set of tyres. All 4 tyres are of the same model, type and brand ensure uniform wear and increased service life.
- Tyre age, or natural shelf life. Tyre operation life limited by the manufacturer applies even to cases when tyres are rarely used. They are still subject to oxidative process and gradual cracking. After the expiration date, tyre failure can occur at any critical moment.
What to do to increase tyre life:
- Observe storage rules for tyres.
- Ensure proper tyre maintenance.
- Follow driving style guidelines.
- Check the degree of tread wear regularly.
- Avoid roads with damaged surface.
- Mount only identical tyres of the same model and brand from one manufacturer on one axle.