A trip on an asphalt highway and a drive along a rain-blurred countryside are two fundamentally different scenarios for the operation of a car. Many SUV owners mistakenly believe that all-wheel drive is able to compensate for the disadvantages of inappropriate rubber, but this is not the case. Exactly. contact-spot The surface tire determines whether the machine will get stuck in the first puddle or overcome the obstacle with confidence.
The choice of specialized rubber requires an understanding of the physics of the process: soft soil requires self-cleaning of the tread, and a solid rocky road - protection of the sidewall from cuts. In this article we will discuss in detail what are dirt-tyreHow they differ from the standard “highway” and how not to overpay for unnecessary characteristics, if you do not plan to conquer the tops.
Incorrectly selected shoes can not only spoil the mood, forcing to tow for hours, but also damage the suspension or transmission due to uneven distribution of the load. Therefore, the issue should be approached systematically, assessing the real conditions in which your transport will be operated.
Tire classification by tread type and purpose
Global manufacturers use a single labeling system, which helps to quickly navigate a huge range. The main parameter is the ratio of time spent on hard surface and off-road. HT (Highway Terrain) These are classic highway tires that are put on crossovers from the factory. They are quiet, economical, but on wet clay turn into skis.
For lovers of active recreation the most interesting category AT (All Terrain). This is a “golden mean”, allowing you to feel comfortable in the city and confidently drive through the forest. The tread here is more aggressive, with large checkers, and the composition of the rubber mixture is often strengthened to protect against chipping. However, it is worth remembering that the noise is higher than that of civilian counterparts.
What is the difference between AT and MT tires?
The main difference is in the aggressiveness of the pattern and the composition of the rubber. MT (Mud Terrain) have deep grooves for self-cleaning from dirt and very rigid sidewalls. They are designed for extreme off-road, but on the asphalt make a lot of noise, brake worse and wear out faster. ATs are more versatile and suitable for daily driving, whereas MTs are a tool for specific tasks.
The most extreme group is MT (Mud Terrain) tires. They are made for mud, swamp and rocks. The tread pattern here is very deep, with wide drainage channels. The sidewalls of such tires often have enhanced protection, which is critical when driving on stony placers. In urban mode, they cause discomfort due to the hum and vibrations.
Seasonality and operating temperature
Air temperature plays a key role in the efficiency of the rubber mixture. Summer off-road models at temperatures below +7 ° C begin to "blown", losing the coupling properties and elasticity. This makes them dangerous even on dry asphalt, not to mention slippery ground.
Winter options, often labeled as M+S (Mud + Snow) or with a snowflake pictogram, remain soft in the cold. However, it is worth distinguishing between winter tires and all-season tires. For harsh winter conditions with icy primers, it is better to choose specialized winter models with spikes or Velcro, as standard mud rubber in ice porridge may not cope.
⚠️ Attention: The use of summer tires on dirt roads in the off-season, when night temperatures drop below zero, is strongly discouraged. Rubber loses elasticity, which dramatically increases the risk of damage to the sidewall on a sharp stone or snag.
All-season tires (All Season) are a compromise. They are not ideal in the heat or in the cold, but allow you not to change the wheels with a slight change in the weather. For moderate climates and non-extreme use, this may be a justified solution, especially if the car is used predominantly in the warm season with occasional departures in the fall.
Check the tire production date before buying. Rubber over 5 years old (regardless of mileage) begins to lose its properties due to drying of plasticizers, which is critical for off-road conditions.
Design features and technologies of protection
When choosing tires for bad roads, special attention should be paid to the structure of the frame and sidewall. Conventional city tires have weak sides that are easy to pierce against a sharp stone or damage on the roots of trees. Off-road rubber manufacturers are implementing various reinforcement technologies.
One popular technology is the strengthening of the sidewall, often referred to as 3P (3-ply) or Reinforced. This means that the side of the tire uses three layers of cord instead of the standard two. This design significantly increases resistance to cuts and punctures, allowing you to reduce pressure to increase the contact spot without the risk of disassembly.
| Type of protection | Description | Under what conditions |
|---|---|---|
| Standard Sidewall | Normal sidewall, 2 layers of cord | Asphalt, light ground, snow |
| Reinforced / 3P | Reinforced, 3 layers of cord | Rocks, roots, heavy ground |
| Kevlar Belt | Insertion of Kevlar in the shoulder zone | Extreme offroad, rocks |
Self-cleaning technology is also important. In the mud, the tread quickly clogs and the tire becomes smooth. Special grooves and checkers shape in dirt-tyre contribute to the extrusion of dirt when the wheel is rotated, restoring the clutch. Without this property, the car turns into an unguided projectile floating on slime.
☑️ What to look at when visually inspecting a tire
Influence of size and profile on passability
Many owners aim to maximize the diameter of the wheels, believing that this will automatically increase the passability. Indeed, greater clearance allows you not to catch bumps with your belly, but the medal has a reverse side. Installing a non-standard size requires reconfiguration of the speedometer and can lead to overloading of the transmission.
A high profile tire is often more useful off-road than just a large diameter. With a reduction in pressure high-profile It works as an additional cushion, bending obstacles and increasing the area of contact with the ground. This is especially true in the sand and snow, where it is important not to fail.
However, increasing the diameter changes the gear ratio of the main pair. The engine becomes harder to spin the wheels, the dynamics of acceleration decreases and fuel consumption increases. In some cases, if the difference in diameter is large, it may be necessary to replace gears in gearboxes (elevator not only suspension, but also "iron").
⚠️ Attention: Before installing larger diameter wheels, be sure to check the space reserves in the arches with fully turned wheels and compressed suspension. Friction of the tire against the sparser or body can lead to fire or destruction of the body element.
Tyre pressure: key parameter of cross-country
One of the most effective and free ways to improve patency is to adjust the pressure. On hard coatings, high pressure is required to minimize rolling resistance and wear. But on sand, snow or loose mud, pressure is necessary. reduce to 0.8–1.2 atmosphere.
With a decrease in pressure, the tire flattens, the contact area increases many times. The car literally floats on the surface of the ground without falling through. In addition, a soft tire better fits the bumps, increasing traction on stones and logs.
The golden rule of offroads: the softer and looser the soil, the lower the pressure in the tires should be. Don’t forget to fill them up before you go on the road!
For frequent trips to nature, experienced drivers recommend installing a tire pressure control system (TSDSH). It allows you to change the pressure directly from the cabin or without removing the wheels from the car, which saves time and effort. If there is no such system, be sure to bring a high-quality compressor with a margin of performance.
Rubber care and extension of service life
Aggressive off-road operation shortens the life of tires. Dirt, chemical reagents on the roads, sharp stones and overheating are all enemies of rubber. After each major trip, it is recommended to wash the wheels, cleaning the tread from stuck stones and dirt, which may contain aggressive substances.
Visual inspection of the sidewalls should become a habit. Even a cut can cause sudden depressurization at the most inopportune moment. Small damage can be sealed with tourniquets, but if the cord is damaged, the tire is better to replace or use as a spare.
Rotating the wheels (running around or cross-rotating) helps ensure uniform wear. On SUVs with plug-in all-wheel drive, the rear tires often wear out faster due to the features of weighting and transmission operation in 2WD mode. Regular reshuffling will prolong the life of the kit as a whole.
How to store tires in the off-season?
Tires with discs are stored lying down (stop) or suspended behind the disk. Tires without discs are only vertical, rotating them periodically to avoid deformation. The storage area should be dry, dark and cool, away from heating appliances and oils.
Frequently Asked Questions (FAQ)
Can I drive mud rubber (MT) on asphalt all the time?
Technically possible, but not recommended. MT tires have a tougher rubber composition, which leads to an increase in the braking distance on wet asphalt. In addition, they create a high level of noise and wear out faster when moving on a hard surface due to uneven abrasion of checkers.
Do I need to do a break-down after replacing the tires?
By itself, replacing tires does not require adjusting the angles of the wheel installation. However, if you change the dimension (diameter or width), it can affect the geometry of the suspension. If you are putting tires of the same size, a crash-convergence check is desirable if there are suspicions of suspension problems or uneven wear of old rubber.
Which is better for snow: spikes or Velcro on an SUV?
For loose deep snow, the tread pattern and the width of the tire are more important. For rolled snow and ice, spikes are more effective. However, on clean asphalt, the spikes make noise and brake worse. For mixed conditions (city + light snow) often choose a quality "Velcro" (friction tire) with the marking M+S and snowflake.
How often should I check the tire pressure before I leave?
It is recommended to check the pressure before each long exit, always on the "cold" tires (before the start of movement). Temperature drop (for example, leaving a warm garage for frost) can significantly change the readings, so pressure correction is a mandatory safety procedure.