About Tires

The tires on your vehicle are of utmost importance for your safety and comfort. You must choose tires that are appropriate for your vehicle, your budget and the type of use you make of your vehicle.

Automotive tire technology has improved dramatically over the years. Improvements in construction, geometry and materials have significantly increased the durability and efficiency of tires for all types of vehicles. At Autotech Performance, we can help you choose the best tires for your vehicle and ensure your safety and driving pleasure!

What you should know about tires

Tires come in a variety of sizes and have different characteristics. You should never install tires of different sizes or types on a vehicle. Each tire has specific maneuverability characteristics.

In addition to the registration of the model and manufacturer names, each tire is characterized by a coded sequence molded on its sidewall. For example, a tire with the following designation P215 / 65R15 89H can be described as follows:

  • P: It is designed for a passenger car (Passenger vehicle)
  • 215: its width is 215 mm (about 8 1/2 inches)
  • 65: it has a 65% profile – the tire’s height equals 65 percent of its width
  • R: it’s a Radial tire; B would indicate a belted diagonal carcass tire; D (for diagonal) would indicate a diagonal carcass tire
  • 15: this tire is suitable for 15 inch wheels
  • 89 is the load capacity index of the tire; 89 corresponds to 580.66 kg or 1279 lbs; this number multiplied by four (= 2322.64 kg or 5116 lbs) indicates the total weight that must never be exceeded by your vehicle and any additional load it could carry.
  • H is the speed code that indicates the maximum speed allowed for the tire; for example, the H code corresponds to 210 km / h, which is the norm for most passenger vehicles.

The wear index of the tread is also written on the tire. It indicates “how fast” the tire wears. For example, a tire with an index of 420 should last approximately 4.2 times longer than a tire with an index of 100. It is understood that the conditions of use of the vehicle and the type of driving may affect the performance of the tire. wear in different ways. This index should not be used to compare tires of different manufacturers.

The traction index qualifies the capacity of the tire to be braked on a wet road surface. This index is measured in braking in a straight line and does not qualify the grip of the tires in turns.

The temperature code indicates the resistance of the tire to heat: the code “A” corresponds to the greatest resistance while the code “C” represents the level of minimum resistance currently required for standard vehicles.

The date of manufacture of the tire is also written on the inside edge of the tire, near the rim. The last 4 digits of the serial number (called DOT) indicate the week and year of manufacture: for example, 1107 means that the tire was manufactured in the eleventh week of the year 2007. Note that the life of a tire is 6 to 7 years old. It is recommended that you check these numbers on all the tires you buy to make sure they are not too old. Tires begin to deteriorate after 6 years, even if they have never been mounted on a vehicle.

The maximum tire pressure is printed on the sidewall of the tire. It must never be exceeded!

Check your vehicle owner’s manual or look in the driver’s door for the recommended tire pressure for your vehicle. You should regularly check the tire pressure to maintain the recommended pressure and detect any slow leaks. Note that a tire can lose up to half of its pressure without it appearing to be flat.

Maintaining adequate pressure is probably the most important factor in ensuring tire longevity. Low air pressure is the main cause of tire failure. With well inflated tires, the suspension of your vehicle works better and you get a better handling and a better mileage.

Excessive or insufficient pressure can be detected by examining tire wear:

  • If the tread is worn outside and inside, the tire is insufficiently inflated;
  • If the tread is worn in the middle only, the tire is too inflated.
All tires have wear indicators that indicate when the tire needs to be replaced: if you see a solid bar across the width of the tire, it’s time to replace it!

Today, most vehicles are equipped with a pressure control system that indicates any discrepancy between the prescribed and actual pressure of the tires. The system monitors each wheel independently. Only wheels marked “PAX System” can be controlled by such a system.

Wheel alignment is also an important factor in minimizing tire wear. Properly aligned wheels greatly extend the life of the tires. The type of tire wear can indicate if the wheels are out of alignment. Note that the alignment must be done on all four wheels at the same time: an alignment made only on the front wheels will cause the accelerated wear of the rear tires.

Radial tires should be swapped regularly back and forth to even out wear – however, they must remain on the same side of the vehicle.

Most vehicles are now equipped with a space-saving spare tire. It is much lighter and less durable than a regular tire. The inflation pressure is usually higher than for a standard tire because of its small size. The pressure in the spare tire should be checked at least once a year to ensure that the spare tire is functional in an emergency.

How to change a tire in an emergency:

  • Stop in a safe, flat place – continue driving slowly over the puncture to the safe place
  • Turn on the hazard warning lights – pull the parking brake and engage the car at “Park” or “1st gear”
  • Remove the spare tire and the jack from the boot
  • Follow instructions on jack or owner’s manual
  • Place the jack as indicated and start lifting the car
  • With the key in a horizontal position on a hub bolt, use the foot to loosen each bolt counterclockwise
  • Raise the car until the wheel no longer touches the ground – remove the bolts
  • Replace the defective tire with the spare tire and install the bolts
  • Get off the car until the tire touches the ground
  • Tighten all bolts with the wrench and foot clockwise
  • As soon as possible, repair or replace the defective tire and return the inflated spare tire to the trunk for later use.

What are tires made of?

The tires are made of fabric, steel and rubber. Mounted on the wheels of a vehicle, they ensure contact between the vehicle and the surface on which it rolls. Every modern car tire supports about 50 times its own weight. The compressed air in the tire supports 90% of the load while the complex structure of the tire – fabric, steel, rubber – supports the remaining 10%.

The wheels are metal cylinders that connect the tires to the suspension system. Although the wheels are often chosen for aesthetic purposes, their function is no less critical. The wheel is a major element of the suspension: when it is too small, it interferes with braking; when it is too big, it interferes with the driving and maneuverability of the vehicle. Similarly, a wheel too wide causes premature wear of the tire and unduly increases the pressure on some elements of the suspension by moving the center of balance of the suspension to the outside. An unbalanced suspension has the effect of making the vehicle very unstable when cornering. It is therefore important to choose wheels (and tires) of the right size for your vehicle.

The tread is another critical component of the tire. It must provide consistent and strong grip to the road to ensure your safety. Each tread pattern (sculpture) is characterized by the geometric shape of the grooves, bars and spaces. The sculpture is one of the main criteria used to select the tire best suited to each type of driving. For example, when riding on a wet surface, it is advantageous to have a tire whose tread can evacuate the water under the contact area of ​​the tire with the road. Thus, continuous grooves that direct water from the center to the outside of the tire provide the best grip in such weather conditions. For a dry surface, a “no pattern” tread tire would provide the best grip and control of the vehicle! However, since your tires are subject to various road surfaces and variable weather conditions, you must choose a tread pattern that offers both durability and control under normal driving conditions.

On each side of the tire, the sidewall connects the tread to the heel. The flanks have two functions: first, they protect the vehicle by absorbing the irregularities of the road; then, they transfer energy from turns, braking and acceleration to the tire tread. The heels are rubber-coated steel hoops that reinforce the area where the sidewalls of the tire and the rim of the wheel meet. The diameter of the beads determines the size of the tire.

The reinforcing cables are arranged under the tire surface in a crisscross pattern. These are the cables that give the tires their strength. These are classified according to the orientation of the reinforcing cables that run through them:

 

  • In a diagonal carcass tire, the ropes are crossed diagonally between the plies – or layers – of the tire;
  • In a belted diagonal tire, there are two or more layers of diagonal cables to which stabilizer belts are fused directly under the tread;
  • In a radial tire, the cables run through the tire in a pattern of hoops from one heel to the other.
The radial tire has reinforcing plies limited to the tread of the tire. The lack of diagonal reinforcement of the sidewall makes the radial tire more flexible, which gives it a better grip and a longer life. It is also what gives it the appearance of being insufficiently inflated.
X
How to find the right tire size?