A car manufacturer usually assigns tire sizes to your car. These are approved and must be respected to guarantee good security and good performance of your tires. This information is there to help you maintain your tires and choose your new tires when you decide to change them. Among them are the load index and the speed index. What are they for and is it possible to change them on winter tires?
WHAT IS THE SPEED AND LOAD INDEX OF WINTER TIRES?
You have undoubtedly noticed the small markings on your tires. This is the tire marking . Among this information, you will find, from left to right, the width of the tire in millimeters, the height of the sidewall in % of the height of the tire, the radial structure of the tire, the internal diameter of the tire and finally, its load index and its speed index.
The load index is indicated in numerical code and allows you to know the maximum load that the tires can handle. The speed index is written with an alphabetical code and indicates the maximum speed at which the tires can roll.
IS IT POSSIBLE TO CHANGE THE LOAD INDEXES OF YOUR WINTER TIRES?
When you change from summer tires to winter tires, for example, you can buy tires with the dimensions recommended by your manufacturer , an equivalent load index and a speed index of two letters lower . Indeed, certain rules apply to the dimensions of your tires and it is important to know them.
CHANGE THE LOAD INDEX OF YOUR WINTER TIRES
It is prohibited to choose a lower load index than your winter or summer tires. You are required to comply with your vehicle manufacturer's rules regarding the Total Authorized Load Weight (GVWR) in kilograms. You can therefore choose an equivalent or higher load index if necessary.
To find out your load index, you can refer to the table below and compare with the numerical index indicated on the sidewall of your tires:
CHANGE THE SPEED INDEX OF YOUR WINTER TIRES
In winter, speed is often reduced due to weather conditions (rain, slippery, snowy, icy roads, etc.). For this reason, it is possible to fit winter tires with a lower speed index. The law allows up to 2 lower indices.
To find out the speed indices that you can choose, you can refer to the table below:
Attention : If you choose a lower speed index, you will have to adapt your driving . You will also need to bring a sticker visible on the windshield of your vehicle to indicate that you have a speed index different from that provided by the manufacturer.
WHY CHANGE THE SPEED INDEX OF WINTER TIRES?
A lower speed index allows better traction on snowy surfaces . The cost of tires is also more attractive since if you decide to equip yourself with winter tires, all 4 wheels must be changed, which incurs costs which can be significant depending on the tires.
It can sometimes be difficult to change your winter tires, especially since depending on your journeys, they may not not drive on certain restricted roads . You must therefore equip yourself with additional snow equipment . Fortunately, there is an alternative that can be used on dry ground , snowy or icy roads and on roads regulated by signs B26 and soon sign B58 which makes the use of special equipment mandatory during the winter period. These are Musher anti-slip over-tyres . This approved over-tire allows you to ride at speeds of up to 50km/h on snowy surfaces and is resistant for 150 km on dry roads.
And soon available for purchase, the premium over-tyres will allow you to drive 150 km on dry asphalt, ideal for enjoying your mountain vacation peacefully and legally!