Tire speed index - how does it affect driving safety?
Content
Proper tires are the foundation of the problem you need to take care of if you want to travel safely in your vehicle. The tire speed index determines the maximum speed at which a vehicle can travel. Where is it and how to read it? Check out what you need to know about this notation!
What is the tire speed index?
Want to know what the tire speed rating is? This is a designation indicating the maximum speed at which a vehicle can travel on a given tire. This parameter is indicated by a letter (for example, y, h or v) and is determined in kilometers per hour in laboratory tests. During them, the tire is pressed against the drum, which moves at a given speed. The moment a tire reaches its tensile strength is considered its speed index. This designation is also called the tire symbol, rate or speed class.
Where is the speed index class?
The speed rating is printed on the sidewall of the tire, just below the tire size information. Vehicle manufacturers post information about the permissible speed class of tires in several other places, such as:
- vehicle manual;
- factory plate;
- speed index table;
- stickers (on the gas tank flap, on the threshold, on the driver's door pillar, in the trunk area).
So you don't have to worry about not finding this mark.
How to choose a tire speed index?
For example, a tire speed rating might be 88H. This means that a car with these tires can travel at a maximum speed of 210 km/h. Could there be inaccuracies? The rules prohibit the installation of tires with different speed designations on the same axle. However, it is worth paying attention to whether the car manufacturer allows the use of a higher speed index on the front axle, and tires with a lower index on the rear axle.
Winter and summer tire speed index
Now it is worth paying attention to the difference in the speed index between winter and summer tires. Certain exceptions are allowed.
Summer tire speed class
In the case of summer tires, tires with a lower or higher coefficient cannot be installed - it must comply with the manufacturer's recommendations.
Winter tire speed class
According to the regulations, the use of winter tires with an index lower than, but not lower than Q - up to 160 km / h is allowed. Please note that tires other than those recommended may wear out faster.
Installing tires with the wrong speed index - what are the risks?
What are the risks of using tires with the wrong speed index sign? This may include, among others:
- busted tire;
- loss of control over the car - especially when cornering;
- worse grip - loss of stability;
- longer braking distance;
- poor steering response.
The use of tires with a speed index other than the recommended one also reduces driving comfort. These tires are stiff and have more rolling resistance, resulting in increased fuel consumption. Therefore, think carefully about the selection of tires for this car.
Speed index and compensation
In the event of a collision or accident with a car with tires of different indexes, can the insurer refuse to pay compensation due to you? Unfortunately, this can happen. Insurance companies include various items in the terms of the contract, including but not limited to tire information. They take into account their condition, speed class and many other parameters. Therefore, before signing insurance documents, it is worth asking the consultant if they contain such provisions and how they affect the possible compensation for the damage received.
Why is the tire speed index so important?
The corresponding tire speed indicator in the car ensures, above all, safety while driving. Using tires with lower or higher indexes is dangerous both for you as a driver and for other road users. Such a vehicle is difficult to drive and can lose traction, which only puts you in danger of an accident. Therefore, before buying tires, make sure they have the correct tread pattern, size, load capacity and speed. Be aware that you can get fined for the wrong tire!
What is Tire Load Index?
The load index of a tire does not match its speed class. It informs about the maximum load that the tire can withstand when the car is moving at maximum speed. This value is always provided by the manufacturer. You will find it on the sidewall of the tire or on the nameplate in the driver's door. The load capacity is indicated in numbers, but is expressed in kilograms. It is very important to ensure that the total load capacity of all tires on your vehicle does not exceed the total weight of the vehicle.
You already know how important tire speed and load index are. Remember that the speed class for summer and winter tires is different. If you want to drive safely on the roads with your car, you must take care of the right tires! If you do not have the opportunity to choose this coefficient yourself, it is best to contact specialists. You will be able to travel in your car without fear, and in the event of a collision, you will avoid unpleasant consequences in the form of non-payment of compensation.
