Question and answer
What tyre size do I need?
The easiest way to find out is to read the code on the current tyres. The car's instruction booklet will also tell you which tyres are suitable.
How do I read a tyre size?
The size of a tyre is expressed in width (in millimetres), height (percentage of width), rim size (in inches). An example: "215/45R17" represents tyres that are 215 mm wide, have 97 mm cheek height and fit on a 17-inch rim.
Carrying capacity and maximum speed can be mentioned as possible additions. These are not used directly, but read from a table. The maximum speed is expressed in letters from M to Z, where M stands for a maximum of 130 km/h and Z for (much) more than 250 km/h. The load capacity, also known as "load index" ranges from 63 (272 kg per tyre) to 121 (1,400 kg per tyre).
How does this system select a tyre?
The database lists the tyre size, top speed and maximum permissible weight for each car. Based on this, possible tyres are displayed. If several companies offer the same tyres, the cheapest will be selected automatically.
Do I need summer or winter tyres?
Summer tyres are best in summer. They make little noise, have optimum grip and can withstand high temperatures. Winter tyres make sense at temperatures below 7 degrees and have a better tread for dispersing water and snow (at the expense of rolling resistance and noise). Four-season tyres are not as good in summer as a summer tyre and not as good in winter as a winter tyre, but have the advantage that they can be used all year round.