What causes a flat spot?
While driving, your tyres heat up and deform naturally when in contact with the road. This is what gives them the flexibility required to absorb road imperfections.
When your vehicle is parked, the tyres are pressed against the road surface and tend to flatten at their point of contact. As they cool, they may keep this slightly flattened shape. This is how you end up with a flat spot.
Usually, as soon as you start to drive again, your tyres will warm up and the deformation will quickly disappear. But, in certain circumstances, it may persist.
What factors make flat spots worse?
Certain factors can accentuate flat spotting, with the risk that tyres do not regain their original shape:
Parking duration: the longer the duration, the more tyres tend to flatten. If your vehicle is parked for several months, there is more chance of the flat spot becoming permanent.
Parking conditions: changes in temperature, and especially very cold nights, can cause the tyre rubber to harden and set in its flat form.
Heavy loads and under-inflated tyres: a heavily loaded vehicle and insufficient tyre pressure increase the risk of flat spotting.
Tyre type: all tyres are not equal when it comes to flat spotting. Wide, low tyres are less likely to flatten because they have a larger surface area in contact with the ground, meaning the load will be more evenly distributed. On the other hand, high performance tyres designed for fast driving are more susceptible to flat spotting because their structure makes them more likely to remember their parked shape.
3 tips to reduce tyre flat spotting
It is difficult to completely avoid flat spotting when you leave your vehicle parked for a long time, but you can take a few simple precautions to reduce the phenomenon:
Avoid subjecting your tyres to adverse conditions such as under-inflation, heavy loads, low temperatures etc.
Check and adjust your tyre pressures before driving your vehicle after it has been parked for a long time
If your vehicle is going to be parked for several months, if possible, try to raise it so that the tyres are no longer in contact with the ground, for example, set it on blocks or tyre cushions specifically designed to minimize flat spotting.