If you want to drive safely in the cold months, you should equip your car with winter tires. But should you buy new ones, or are the old ones still in good condition? Here's how to find out.
Why they need to be changed
There are two reasons. The first is legal: the requirements in Bulgaria are between November 15 and March 1 to use winter tires or those with a tread depth of over 4 mm. This is not an arbitrary decision - according to experts, it is necessary for the car to be as stable as possible on cold, icy and snowy roads.
The second reason is in the material. Over time, the rubber changes, becomes softer, has less grip and then even a normal tread does not give good results. It is your responsibility to carefully examine whether those tires you have from last year are still usable or not so reliable anymore.
Here's how to do it.
Check the tread
The easiest way is to measure the tread depth. Do it in several places, but especially check the most worn ones. If even in one area the depth is less than 4 mm, there is nothing to think about - these winter tires are no longer suitable for use. And any police officer who stops you on the road will remind you of this.
These models are designed with special grooves. They have such a depth and direction that they easily push water and snow aside and provide resistance on ice. But when they wear out, they stop performing their function well.
Look for wear indicators
Most modern winter tires have special wear indicators. These are raised details inside the grooves. Their height is the maximum wear that the manufacturer has set for their product. So if the lugs wear out so much that they reach the indicator, it's time to replace them, even if you measure more than 4 mm deep.
Check for cracks
But the lug itself is not enough - winter tires must be in good general condition. Carefully inspect each one along the edges and sides, outside and inside. Look for any cracks, cuts, bumps, bulges, deformations or delaminations. All of them will show you that safety is no longer guaranteed. If the changes still seem insignificant to you, seek the opinion of a specialist.
Assess the wear
If the surfaces are not worn evenly, this can affect the behavior of the car on slippery roads. But it also means that the car itself is not upright and it is a good idea to have it checked at a service station.
Check the age
Rubber ages over time, affected by sunlight, heat, cold, and storage conditions. So even if it looks perfect, an outdated winter tire no longer has the necessary grip. Manufacturers usually give instructions on how many years the material will last in good condition, but even the best of them recommend less than 10 years under good storage conditions.
And to find out when it was manufactured, look for a DOT/TIN code written on the wall. The last four digits are the week and year of manufacture and will guide you whether it is really worth it.