Tire code#Speed rating

The speed index, speed rating and speed category are for tires to the maximum allowed speed. It is included in the tire designation as the last character and can be read on the sidewall of the tire. A breakdown of all tire designations can be found under the concept car tires.

The maximum speed indicates the maximum speed at which the manufacturer with correct tire pressure for proper continuous operation is guaranteed. Otherwise there is a risk that the tread separates from the carcass.

To determine the speed of the index registered in the vehicle card design speed ( bbH ) is assumed. For vehicles with a first registered before 1 May 2009 a security surcharge according to the following formula must be considered in addition to bbH: bbH * 1.01 6.5 km / h

As an example, the results for a car with a bbH of 205 km / h safety margin of 205 * 0.01 km / h 6.5 km / h = 2.05 km / h 6.5 km / h = 8, 55 km / h

Overall, therefore, the example vehicle must drive a tire that matches a speed of 213.55 km / h. This speed index H is no longer sufficient and it must be used a V-rated tires.

A car with a bbH of 205 km / h, therefore, requires a minimum speed rated tire H.

The approval of the vehicle type by the KBA ( Federal Motor Vehicle Office) it is left to the vehicle manufacturer to see if it is sufficient that value or whether it explains a tire a higher speed class is necessary. This entry in the vehicle documents is not binding and it can be mounted on the vehicle, a tire with a smaller velocity index, if the above formula allows a tire smaller index.

In addition, all-season and winter tires can be fitted, which have a lower speed index if (a ) is mounted in front of the driver a sticker at the speed limit and ( b ) will not drive faster than allowed by the tire labeling.

The following speed classes are defined:

The abbreviation ZR generally applies to tires over 240 km / h and is often provided with a supplement. Example: 225/ 45 ZR 17 Y. If the additive is provided in brackets (eg 295/30 ZR 21 (Y )) of the tires can be ridden over 300 km / hr.