Most drivers buy new tires only every few years. Their routine is correspondingly low - for example when it comes to the question of which winter tires even fit on their own car.
"I need new winter tires. How do I find out which size I need?reader question
Answer by Hans-Georg Marmit, Motor vehicle expert of the expert organization KÜS: “Determining the right tire size for your own car can actually be complicated. It is still relatively easy for owners of the old 'vehicle license'. You will find the permissible dimensions there under numbers 20 and 21 or 22 and 23. Additional sizes are often listed in field 33 under ´Remarks`.
It becomes more complicated when the 'Registration Certificate Part I' introduced in 2005 replaces the vehicle registration document in one's own car. There is only the smallest permissible size specified. The remaining dimensions can be found in the EU declaration of conformity included in the purchase of a new car, also known as COC paper. The list is not exhaustive. Here one asks best the expert. Alternatively, the big tire manufacturers offer search engines on their websites, which use the vehicle data to determine the appropriate tires on the corresponding rim dimensions. Incidentally, the tire size is always in connection with a released rim. Regardless of the standard rims, there are of course still special wheels with test certificates, which extend the usability scope even more.
Mostly several different dimensions are already allowed as standard. Then optics, costs and purpose play a role. The larger the rims and the wider the tires mounted on them, the better the car usually looks. In general, the price increases sharply with more diameter and footprint. However, it may also happen that rarer commercially available tire sizes represent the most expensive variant. Beyond the optics, wide tires usually offer other advantages as well: at least on dry roads they brake better. And also the cornering stability increases. However, wide tires are more susceptible to aquaplaning and increase fuel consumption. At the same time, they offer less suspension comfort. "