An article on how to determine the wear of car tires, and what affects it. At the end of the article - a video about defects in car tires.
The content of the article:
How to check tire wear? The answer to this question saved many drivers not only from getting into an accident, but also from having to pay a fine. The main thing is to put your knowledge into practice in time and, when the maximum allowable wear is reached, change tires.
When to change tires. Causes and effects of wear
The average tire life is 5 to 7 years. Most manufacturers define a service life of 10 years, but in reality, replacement is required for about 6 years of service.
Of course, the wheel can last up to 10 years if the tire is made of quality material, the car is used lightly and on a good road, and the owner carefully monitors the condition of the wheels and the car as a whole.
But in reality, keeping a car in perfect condition is quite difficult, and the times when a car was bought to “boast”, and not for business, have long sunk into oblivion. Today, the car owner exploits his iron friend to the maximum, and does not shake, as if over the greatest treasure. And the tires in the process of work receive the load (and not small) in the first place.
Factors affecting tire wear
Road surface quality
The road has the greatest impact on the condition of the tires. Unfortunately, the perfect asphalt pavement remains something of a fantasy, especially in smaller towns. Road roughness, pits and potholes do not have the best effect on the condition of the tread.
Intensity and features of operation
A worn tire is an indicator not only of the condition of the road, but also of the driver's skills. The tires of a reckless motorist will fail much earlier than those of a calm and experienced car owner.
Caring for the wheels and the machine as a whole
Regular checks of the condition of the car, attention to the needs of the "iron friend" and regular diagnostics can significantly increase the life of tires.
Rubber quality
Economy at the expense of quality can not only affect safety, but also require replacement of rubber much earlier than is usually required.
Suspension condition
Malfunctions of the suspension system do not affect the condition of the wheels in the best way.
Wheel imbalance and other causes
A worn out tread can cause a lot of trouble and jeopardize the safety of the driver and passengers of the vehicle, as well as the car owner's wallet.
What are the dangers of worn tires?
- The grip of the wheel with the road surface is reduced. This is fraught with skidding when cornering and braking, especially on wet/icy surfaces.
- Decreased vehicle performance in off-road conditions.
- Increased risk of tire damage. A leaky rubber puncture is only a matter of time.
- High risk of hydroplaning.
The maximum allowable abrasion rate of summer tires is up to 1.6 mm over the entire tread surface. For winter - 4 mm. For trucks - 1 mm.
These indicators are the limit prescribed by law, but from a safety standpoint it is recommended to change the rubber earlier, when the level of abrasion is 1 - 3 mm less.
Tire wear index
Each manufacturer is required to make markings on the side of tire products in accordance with international requirements. Initially, this standard was used only in the United States, but gradually spread throughout the world. In addition to the country of manufacture, model, purpose, direction of rotation and other characteristics, the level of wear resistance is indicated on the side of the tires.
Treadwear- definition denoting the coefficient of wear resistance. A Treadwear of 100 (average) assumes 48,000 km on standard road surfaces, which are typical of the test track.
Of course, in natural conditions, this indicator is not so accurate - the quality of the road, driving style, weather conditions and other factors significantly affect tread wear and service life. But, paying attention to the index, you can still determine the level of tire wear resistance.
Methods for determining tire wear
The wear level should be checked regularly. This will avoid not only a fine from the state traffic inspectorate, but also reduce the risk of trouble on the road.
There are several ways to determine the degree of tread wear.
Method 1: Check the tire wear indicator
An indicator is a tread block located inside the tread recesses. Its height is equal to the allowable wear rate (1.6/4 mm). If the tread is worn down to the level of the indicator, then the rubber must be replaced immediately.
To find the location where the indicator is located, examine the side of the tire. Opposite the tread block, a small stamp is usually applied in the form of a triangle, the manufacturer's logo, a snowflake, or the abbreviation TWI.
Recently, digital indicators have become widespread. On the surface of the tread there are numbers that show the level of deepening. As they wear, they are erased, starting from the largest in value and ending with the smallest and most “deep”. For example, if only the numbers 2 and 4 remain visible on summer tires, then this is a signal for an early tire change. After the number 2 disappears, the tire has reached its maximum wear level and needs to be replaced immediately.
Method 2. Use a special meter
The indicator is not always accurate, so it is advisable for the driver to purchase a tread depth gauge. With the help of this small and inexpensive device, the car owner can independently control the level of abrasion in several places.
Method 3. Use a coin
If attrition is in doubt, and the meter was not at hand, you can resort to using a 10-kopeck coin. It is placed with the inscription "kopecks" in the groove of the tread.
The word "penny" should not be visible. If it reads well, then the tire should be changed or subjected to a more thorough check.
These methods are used to determine the allowable tire wear that occurs evenly. But often, under the influence of a car malfunction or other factors, the tread wears out in a completely different way than it should be. To find out if there are any unnatural damage, you need to carefully inspect the wheels.
How to visually detect tire wear
Protector worn in the middle
If the rubber is more intensively erased in the middle of the wheel, then the greatest load as a result of friction falls on this particular area.
Possible reasons:
- The tire is unevenly attached to the roadway. Most often this happens if the tire pressure does not meet the manufacturer's requirements.
- Another reason is the pressure drop as a result of temperature changes. For example, during frosts, the pressure in the chamber decreases, and after the temperature rises or the chamber warms up during movement, it rises and often exceeds the permissible norm.
- The wheels are over-inflated. This can happen due to driver inattention or for a specific purpose - some people try to reduce fuel consumption in this way.
Rubber worn out around the edges
If the wear is much stronger at the edges than in the center, you should be on your guard.
Possible cause is too low pressure. In this case, the tire is prone to permanent deformation and the tread does not adhere to the road surface evenly. To avoid such a nuisance (and the operation and durability of the suspension depend on an underinflated wheel), you should regularly measure the pressure in the chamber, especially in winter.
The leading edge of the tread pattern is intensively erased
If the corners of the pattern are worn unevenly (the leading edges are smoother, and the rear edges are practically not worn), this indicates insufficient rotation of the wheel.
Possible reasons: problems with the operation of the suspension, failure of ball bearings or bearings.
This happens quite often; if such wear is found, the machine should be checked for the serviceability of the suspension.
Tire excessively worn on one side
The culprit is the same loose fit to the road surface.
Possible causes: suspension malfunctions or unadjusted camber.
Similar symptoms are also characteristic of trucks - the cause is excessive load on certain parts of the wheel.
Cracks on the sides of the tires
Possible causes: off-road driving, low pressure, poor quality tires or long service life.
Such deformations usually occur when hitting pits and potholes with insufficiently inflated (or vice versa, pumped over) tires. If the wheel pressure meets the requirements, then the bumps on the road are smoothed out due to a kind of depreciation. But if these requirements are violated, the wheel is subjected to a load and takes all the impact on itself, deforming under pressure from the outside.
Cracks may indicate that the quality of the material of manufacture leaves much to be desired. They also signal the old tires and the need to change them to new ones.
Bulges on the sides of the tires
Possible causes: Damage to the rubber as a result of hitting a hard surface with the side of the wheel.
The bulges appear some time after the impact. A wheel with such damage becomes dangerous for operation; it is advisable to replace the tires as soon as possible.
Dents on the tread
Possible reasons: insufficient depreciation, unadjusted wheel alignment.
The shock absorber is responsible for smoothing and evenly distributing the shock load during movement. If it fails, the wheel suffers first of all, receiving an increased blow to certain sections of the tire. As a result, dents and bulges are formed on the entire surface of the wheel.
At the first sign, you should drive the car for diagnostics and check the suspension.
Wear in the form of individual spots on the tread
Possible causes: heavy braking, a sharp turn or skidding of the car with wheel locks.
Also, the cause may be a long fixed load on the same section of the tire, for example, when the car is left for a long time without movement, leaving to rest or not using it in the winter.
With regular checks, it's hard to miss the moment when it's time to change tires or worry about the causes of abnormal wear. Taking good care of your car can help you avoid a lot of trouble and fix problems before it's too late.
It's no secret that during operation, a set of tires is subject to wear and over time it has to be replaced with a new one. But not many people know that tires can already have a tendency to accelerate wear at the acquisition stage. What is the reason for the short life of new wheels?
What should be checked when buying new tires?
Below are tips on what to look for and how to proceed when buying new tires. They are pretty simple.
1. Ask about storage conditions
Proper preservation of tires in a warehouse is a guarantee of their long service life. If there is an opportunity to get to the warehouse, be sure to use it. Sometimes this can be done at the time of the final stage of issuing tires to the buyer.
If tires are stored:
- In a damp room or with high humidity.
- In a horizontal position, in a stack (if without rims).
- Under direct sunlight.
- In a room with high air temperature.
- No covers or capes.
Then, in this case, it is better to refuse to purchase them. The thing is that as a result of such storage, microcracks, deformation and damage may appear on the rubber. This is due to the loss of rubber elasticity and the wrong way to preserve tires. If the tires have the listed defects, then it will not last long. Maximum - one or two seasons.
2. You need to look at the date of manufacture
If the wheels were produced more than three years ago at the time of their review, then it must be understood that the rubber composition of such tires has already lost some of its useful properties and has lost some of its elasticity. During subsequent operation, insufficient traction and destruction of rubber may be revealed. Although, theoretically, tires can be stored for five to eight years without losing their best qualities.
3. It is necessary to purchase wheels in the center where there is a tire service
In this case, when installing new wheels, hidden defects may be revealed and the seller will not be able to refuse to replace the damaged tire with a new one. In addition, a guarantee is usually given for the work of a tire fitting - within the allotted time, you can come and make a claim regarding the installation of tires.
4. The seller is obliged to issue a check
Sometimes this is taken lightly and the check is thrown away. Under no circumstances should this be done. It is the presence of a check that will help to exchange defective tires for a new one.
5. Wash the protector with your fingers
Rubber should not be too soft. The fingers should not fall inward, but only slightly bend the tread - in this case, we can talk about good elasticity, and hence the retained grip properties.
6. Inspect tire sidewalls
They should not have scuffs and even more so cracks / cut fragments. The sidewalls are the bearing part of the tire, and therefore any damage to them can cause an explosion / rupture of the wheel while driving, which is very dangerous.
Outcome: These simple recommendations can make it easier to choose tires and avoid buying defective ones. However, there is still no absolute panacea for low-quality rubber - the main defects are detected only during operation.
Today, uniform tire wear is of great importance. If there are clear signs that the tire is wearing unevenly, you should urgently find out the problem that lies in the incorrect course of the machine.
The main criteria for wear of studded tires:
1) The first thing you should pay attention to is the tread height. As you know, winter tires have a higher tread height than summer tires. But to determine the degree of wear, the limiting wear height is used. If it is reached, the tire loses the most basic characteristics for movement. Winter tires have an average tread height of nine to eleven millimeters. The minimum wear height of winter tires is four to six millimeters.
2) If the car has shock absorber defects, there will be a seal around the perimeter of the tread.
3) If there is increased pressure inside the tire, the tread wears out from the middle.
4) If the tire pressure is too low, the shoulder sidewalls will wear out.
5) When the car is standing for a long time, flattening forms on the tires. If the owner of the car does not plan to use it in any season, he must remove the tires or install it in such a way that there is no downward pressure on the body.
6) If the driver brakes hard, noticeable wear is found in some places of the wheel.
7) If the machine is often driven off-road, there may be sharp edges on the front side of the wheels.
As a rule, the manufacturer soldered rubber pimples into the base of the tread, by which the level of wear is controlled. With full wear, the pimples wear down to the same level as the tread. And American tires have their own tread wear indicator, designated TWI. It is usually indicated by arrows. They are located around the entire perimeter of the tire at a distance of six to eight centimeters from each other.
When does premature tire wear occur?
1) Insufficient pressure inside the tire;
2) Exceeding the load on the car, non-compliance with the requirements for the load index for a particular car;
3) Incorrect driving of the car;
4) Irregular repair, maintenance of the machine;
5) Failure to comply with the rules for mounting tires;
6) Wheel imbalance;
7) The presence of malfunctions in the steering of the machine and the chassis.
When driving on winter roads, the tire resource is significantly reduced, and the degree of wear increases. If the bead is damaged during incorrect installation, the percentage of tire wear increases by ten percent. If chips, cracks are found on the tread surface of studded rubber, then its wear increases by twenty-five percent. Well, if the carcass is stratified, then tire wear is considered one hundred percent.
Typically, the technical wear process is accompanied by an additional percentage of aging due to service life. If winter tires are used for three seasons, then the degree of wear is ten percent. After five years of active use of winter tires, the wear rate is fifty percent.
And in America, a one-dollar coin is used to determine tire wear. It is inserted into the tread groove with President Washington's head down. If Washington's hair is visible, it's time to change the tires due to the onset of their wear limit.
In Russia, to check the degree of tire wear, it is checked using a two-ruble coin. To do this, the coin is inserted upside down with the eagle's head. If the crown of the bird is visible on the surface of the tire, then it can continue to be used.
Every car owner has their own driving style. The wear of winter tires depends on many factors and various modern methods are used to determine it, including folk methods invented by car owners themselves. But there are rules that are dangerous to neglect, because there is a risk not only to get into an accident, but also to run into trouble on the part of inspectors who keep order on the roads.
Car owners scrupulously and carefully select tires, but do not always know how to check the quality of the goods received. New wheels should be carefully examined before being given to a tire shop. Since, on average, motorists change their “shoes” on their cars every two to three years, you need to worry about their quality.
Initial inspection
When thinking about how to determine the condition of tires after purchase, you should carefully consider the surface. Rubber must be uniform in color and texture, free of visible defects and damage. Next, it is worth examining the surface and sidewalls, studying the information printed on them.
Rubber freshness
It is worth checking the production date of the wheels, to find out if it matches the one that was negotiated when buying. The stumbling block for manufacturers, sellers and buyers of wheels is the date of issue and the operational period of the wheels. The first claim that tires do not lose their properties during storage for 60 months from the date of issue. Experienced motorists try not to buy tires older than 36 months, they do not always support the race for "fresh".
Such global giants as Continental, Goodyear and Michelin define a five-year shelf life for rubber and a similar service life, after which the wheels must “retire”. However, storage does not always take place in the right conditions, and therefore car owners are justifiably eager to buy the latest in the tire industry. The only advantage of purchasing the wheels of past seasons is the cost - it is an order of magnitude lower.
Markings and certificates
All tires on all continents undergo mandatory certification, which ensures strict compliance with safety and product quality standards. So, if the marking “E” is indicated on the side surface of the wheels, then the tire is made in accordance with European standards, and if “DOT” - American. In addition, the certificate number must be indicated, and the seller may have all the documentation confirming the quality of the product.
Trust the manufacturer
The presence of various markings is a guarantee of quality. So, manufacturers without fail check tires before release, and at the same time mark the lightest side with a small colored circle, in place of which it is best to install a spool during installation.
Domestic tire manufacturers pass through the technical control service, which makes its marks on the tires: “K” - control, “TK” - technical control or a stamp like “GOOD”, after which the controller number is indicated. In order not to get into trouble, you need to know that the designation of high-quality and defective products is different for domestic and European manufacturers. The factories of the CIS countries mark the marriage in red, and the tires that have passed the test are green, European manufacturers do everything the other way around.
Auto behavior
Knowing how to determine the quality of tires visually, it is worth trying tires in action, feeling their behavior on the road. Trembling of the steering wheel or car, skidding, "swimming" when driving fast and slow - these are signals of low-quality wheels. If the car skids, the tire pressure drops, and the car does not obey the steering wheel, it is worth sending the wheels for professional diagnostics. In order not to risk yourself and your car during such experiments, it is better to shop from reliable market representatives who can guarantee reliability and quality.
Tires are one of the most important components of a car for driving safety. Proper use of summer and winter tires during the season improves handling and saves the car owner money. But some drivers not only postpone changing tires depending on the weather, but also continue to use the same tires for several seasons. At the same time, wheel wear becomes more and more, and the threat that the tires will not cope with holding the car increases.
The tire tread is responsible for connecting the car to the road. This is the outer layer of rubber, which contains a certain pattern, suitable for different operating conditions. For summer tires, the removal of water from the contact patch is relevant, for winter tires - improved grip on slippery surfaces, for off-road tires - maximum cross-country ability. Regardless of the purpose of the tire, one of the important characteristics of the tread is its height or depth. This is the distance from the outer edge of the tire to the "bottom" of the groove. For new modern car tires, the height starts from 5 mm. For ordinary summer passenger tires, this value is 6-8 mm, and for winter tires - 8-10 mm, for SUVs - 15-20 mm.
With wear of the tread (decrease in its depth), the leading properties first of all suffer: the car is more prone to hydroplaning. Winter tires lose some of their properties, which are provided by special sipes and studs. It is important to consider that different brands and models have different rubber composition, so some wheels “run” longer. The driving style also affects wear - more aggressive starts and active braking will shorten the life of the tire.
The critical indicators for tire wear are tread height of 1.6 mm for summer tires and 4 mm for winter.
Height can be measured using rulers with depth gauge or a caliper.
For those who do not have such tools, you can use regular 10-kopeck coin placed in one of the grooves. If the word “penny” is hidden, it means that the tire is almost new and does not require replacement. If the tread covers only the floral ornament on the winter tire, then it will soon need to be changed; if in the summer — the replacement will wait. If only the rim of the coin is hidden, you need to urgently install new tires.
On the left is a worn tire, on the right is a nearly new tire. Photo: AiF / Irina Zverkova
Many modern manufacturers make tires wear indicator(this is a protrusion located perpendicular to the axis of rotation of the tire) or a special colored layer is laid, which becomes visible when the tire is erased. Their manifestation serves as a signal for the car owner to change tires.
It is important to monitor not only the tread depth, but also wear uniformity. To be sure that the wheel is in good condition, it is better to measure the tread depth at different places around the circumference along the entire width of the tire. If the inner or outer part is worn out more, then the wear of the tread is taken into account at a minimum value, and it is better for the owner to check the wheel alignment / collapse of the car.
If the vehicle has frequently been driven on rough roads, climbed curbs, or the tires have been run half-flat, there may be jammed or incompletely broken areas, cuts and cracks. It is better to check their condition at the tire shop before the tire is flat at the most inopportune moment. For example, it may not withstand the loads in a turn, burst and provoke an emergency. You should be especially careful about such damage on low-profile tires.
On average, tires last approx. 6 seasons, after which it is better to replace them. Improper storage and aggressive riding can shorten the lifespan. You also need to pay attention to the expiration date of the tire and the date of its production when buying, because polymers, unlike metal, can break down and lose their properties over time.
If it is not possible to update all four tires, then, as a last resort, you can put new tires on the drive wheels. But just need to change a couple, otherwise the vehicle's handling may be severely impaired.
