Mixed tires
With "mixed tires" the legislator describes the combination of radial and diagonal tires for motor vehicles . Diagonal tires and radial tires are different types of tires. If both types of tires are fitted to a vehicle at the same time, mixed tires are used. Mixed tires on one axle are always not permitted; In the case of cars , either only diagonal or only radial tires may be used on the entire vehicle ( Section 36 StVZO). Since cross-ply tires are only used in oldtimers , this problem of mixed tires rarely occurs in practice.
The tires of a car with radial tires from four different manufacturers or with summer and winter tires is therefore permissible according to §36 StVZO if the prescribed tire sizes are observed. The contradicting assertion, sometimes made by experts, that it is a matter of "impermissible mixed tires", is not true. However, reference is made to the different driving behavior of these tires.
Even if a car with different tire sizes of the same type is fitted with tires on the front and rear axles, it is usually referred to as mixed tires. This combination is fitted as standard on some vehicles. For others, it is only permitted if a general operating permit (ABE) or a parts certificate is available for the accessory wheels used. In any case, disregarding the requirements specified for the front and rear axles will invalidate the operating license .