AH40.10-P-1050-01A General Information on Rim/Tire Conversions

AH40.10-P-1050-01A General information on rim/tire conversions

On vehicles with vehicle documents up to 30.9.05
When tires of dimensions other than those listed as standard in the vehicle's registration papers are mounted within the Federal Republic of Germany, the department of motor vehicles must enter the dimensions of the non-standard tires in the vehicle's registration slip and title. The condition for this approval is a prior, positive appraisal issued by a technical officer at an officially recognized vehicle inspection station (TUV). The appraisal and approval documentation for tire sizes with prior approval from Mercedes-Benz is usually already contained in the listings maintained at the inspection stations. Always observe all national and local regulations when mounting tires in other countries.

Light alloy wheels are only required by law if in the vehicle registration documents under Section 33 to Section 20 up to 23 the restriction A. LM. rim (on light alloy rims) is expressly stated. The designation A. in the vehicle papers merely stands for "on rim," or "on wheel," and does not indicate that aluminum wheels are required.

On vehicles with vehicle documents as of 1.10.05
With wheel/tire dimensions which are not entered in the vehicle documents, either a COC paper (conformance certificate) or a corresponding expert's report on the parts must be available. The permissible wheel/tire combination must be listed in the homologation certificate Part 1 under number 15 or in the certificate of conformity (COC) paper under number 32 and 50 or in the required Technical Inspection Association report.

For all vehicles
General Operating Approval (ABE) is issued for each individual nonstandard wheel by the Federal Motor Vehicle Registry (KBA); approval is always issued in combination with a specific vehicle type. It is usually supplied at the same time as the wheel is purchased and is a precondition for the preparation of the expert's report. With many rim/tire/combination conditions listed in the ABE are to be taken into account (e.g. body change, vehicle modification). The assignment of the speed rating of the tires is based on the maximum speed of the vehicle.

On winter tires with a speed index V (up to 240 km/h) it is to be observed that these have a lower load capacity. These tires are thus not approved for unrestricted use as replacements. The reduction in so-called axle weight allowance may lead to a lower permissible maximum speed.

These facts should be pointed out to customers whose vehicle is equipped with V-tires.

Retail tire suppliers have access to tables containing information on weight capacities and possible reductions in top speed.