Better performance, shorter braking distances, optimum grip – all are affected by tyre temperature. By maintaining the right conditions when using and storing your tyres, you can enjoy their full performance for a long time. What is there to know?
The temperature of your tyres has a major impact on their performance.Tyre temperature and performance on the road
Tyres heat up gradually during use. The shoulder area gets the warmest, especially when cornering. The tyre temperature should be around 60⁰C when driving. To achieve this, the car should be driven for about 30 minutes.
Saving money is one of the benefits of a properly warmed up rubber compound. As it heats up to the right temperature, the rolling resistance coefficient decreases and stabilises. This has a significant effect on fuel consumption, thanks to which the car burns less petrol.
It is important to know that the temperature of tyres changes rapidly during braking. In a car with an anti-lock braking system (ABS), the temperature rises to around 70-80⁰C. In a car without ABS, the temperature can be twice as high. When the car comes to a sudden stop, traces of worn rubber are often left on the pavement.
Heating up of sports car tyres
As mentioned above, the optimum temperature for all-season, winter or summer tyres when driving in traffic is around 60⁰C – this ensures good grip and reduces rolling resistance. However, tyres used intensively on race cars perform best at higher temperatures – from 70⁰C upwards. Why does this happen?
UHP and sports models with a high speed index (W, Y, (Y)) are made from harder rubber compounds that take longer to warm up. In the first few minutes of driving, or when it is cold outside, the tyres need more time to warm up and provide the necessary grip. For this reason, it is not uncommon for onboard computers in sports cars to report the temperature of each tyre, indicating whether it is underheated, adequately heated or overheated. This way, drivers are informed of when their tyres are delivering high performance and optimum durability. It is important to remember that the heat level affects not only performance. It also changes the pressure in the tyre, which affects its traction properties.
Sometimes, during car races, we can also see that the wheels of the cars are covered with special heating blankets in order to maintain the optimum level of degrees Celsius. For example, the temperature of F1 tyres should fluctuate in the range of 90-110⁰C, which can be achieved at race speed.
Tyre temperature A – what does it mean?
If you look at a tyre, you will see the inscription Temperature A, B or C on the side of the tyre. This indicates the tyre’s resistance to overheating, which, among other things, affects tyre life. The letter ‘A’ indicates the best performing products.
Interestingly, the A, B or C temperature rating on tyres was developed by the US Department of Transportation. It used the UTOQ performance rating system in which temperature is one of three criteria evaluated. Tyres are tested on certified machines. Any product sold in the United States must carry the UTOQ marking. It can also be found on many tyre models available on the European market.
It is a good idea to check the temperature markings on your tyres. What are the dangers of overheating tyres?
If you ride with tyres that are underinflated, the dangerous phenomenon of tyre overheating may occur. Overheating can also occur if you drive for too long at the speed limit specified by the tyre manufacturer. In this case, the tyre will heat up very quickly, which can lead to internal combustion of the rubber compound. As a result, the tyre will no longer be suitable for further use.
Overheating a run-flat tyre
A particular example is run-flat tyres, which are designed to reduce the effects of a sudden loss of tyre pressure after a puncture. Their structure allows you to continue driving at a lower speed for a certain distance. This is assumed to be up to 80 km at a maximum speed of 80 km/h, allowing you to reach the repair shop safely. It is important to note, however, that the manufacturer’s recommendations must be strictly adhered to. A loss of pressure can contribute to an increase in heat inside the component, so if you ignore the instructions you could end up with overheated tyres.
Tyre pressure vs air temperature
In this context, it is worth considering the relationship between tyre pressure and air temperature. The lower the value shown on the thermometer bar, the more the tyre pressure drops. For every 10⁰C drop in temperature, the pressure falls by 0.1 bar. On cold days, when readings of -20⁰C are recorded, the pressure difference can be as much as 0.4 bar. It is therefore advisable to regularly check the tyre pressure with a tyre pressure gauge, especially in winter, and to top up if necessary.
Changing and storing tyres and tyre temperature
The weather outside, including the temperature, also has an effect on the tyre’s behaviour on the road. The rubber compounds used in different models vary. Therefore, you should not drive on winter tyres in summer or summer tyres in winter. At the turn of the season, an average temperature of 7⁰C for several days in a row is the limit and indicates that a visit to a tyre technician for a tyre change is needed.
Did you know that...?
Winter tyres perform best at temperatures below 7⁰C. During this time, they retain their optimum flexibility and their design improves vehicle control in difficult conditions. Summer tyres, on the other hand, wear more slowly in hot weather and disperse water better in heavy rain, while offering high performance also on dry surfaces.
To get the best performance from your tyres, you also need to make sure they are stored correctly. The temperature at which they are stored should not be too high or too low. Cold weather causes the rubber compound to harden, while heat causes it to age prematurely. The optimum temperature is between +5 and +35⁰C. Also, avoid areas exposed to UV rays, which have a negative effect on the condition of tyres.