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Decreto ruote

The need to guarantee road safety, was timely satisfied through the Decreto Ruote (Wheel Decree) 20/2013, which states that replacement wheels (excluding those supplied directly by the vehicle manufacturer) must be subject to approval, in order to prevent products with sub-standard safety characteristics (already listed in the UNECE 124 regulation) from entering the market. At the same time the regulation provides for the opportunity to obtain approvals also for “special wheels” (not possible under the UNECE 124 regulation) introducing national type approval and relative rules.

Donaldo Labò

The last issue of Pneurama contained a detailed account of the round table that took place on the 22nd of May during the last Autopromotec show entitled “Wheel systems: standards, application and protection of legality”.

As illustrated, next September 30, 2015 the exception granted by the Ministry of Infrastructure and Transport will cease, i.e. the possibility of marketing in Italy all wheels in stock and still without approval, manufactured and imported into the European Union before the 30th of November 2014, as prescribed by the – Decreto Ruote N° 20/2013 - in force since the 1st of January 2015, on vehicles belonging to M1 (cars) and M1G (off-road) categories.

Such exception, provided within the - February 24, 2015 Law Decree - is also limited to manufacturers officially approved for mass production by the Directorate General of the DVLA or a Test Center (

The manufacturing date (month/year) is part of the obligatory markings. Below are some clarifications on technical / regulatory details, starting from the pre-decree state of the art.



UNECE approval

Wheel Scheme from Reg. 124 UNECE.

Evidently, being a structural element of the vehicle relevant to safety, and in view of regulating the subject matter, during the early 2000s an international regulation was developed in the UNECE headquarters in Geneva - Reg.124 - approved in 2006, entitled "Uniform provisions concerning the approval of wheels for passenger cars and their trailers".

"Wheel" means a rotating load-carrying unit set between the tire and the axle. It usually consists of two major parts: the rim (on which the tire is mounted) and the wheel disk.


A fundamental distinction is the classification/origin of the wheels. In short:

-“original” wheels: supplied by the vehicle’s manufacturer as original equipment.

“replacement” wheels: supplied as replacements which can be:

a) “from the vehicle’s manufacturer”: supplied by the manufacturer (standard or optional);

b) “identical”, “replicas”, “pattern part”, which do not differ from the original wheels supplied by the manufacturer for a specific model/version of the vehicle in its main technical characteristics (profile, rim diameter, width, offset/inset etc.), thus maintaining the same tire size provided by the approval;

                c) “special: which display different features and sizes from the originals. Generally larger or wider rims, capable of housing tires of different sizes (section diameters and widths) compared to the vehicle’s standard equipment. These are the wheels we specifically refer to when talking about “Tuning”.


Approvals example from Reg. 124 UNECE.

As far as the implementation of the UNECE 124 regulation, it is specified: “it does not apply to original equipment wheels, or vehicle manufacturer’s replacements …It does not apply to – special wheels – which shall remain subject to national approval.”

The approval therefore may include replica replacement wheels and pattern part wheels, whose sizes and technical characteristics, as already stated above, fall within the original ones planned for that model / version of the vehicle. "Special wheels" on the other hand, as decided at the time of approval in Geneva, until a future international standard regulation is produced, would be subject to national approvals.


Manufacturing and mounting requirements as stated by the UNECE 124 regulation, considering the different types of wheels, both steel and alloy, include impact and reliability tests (annex 4 to 9), as well as vehicle fitment checks (annex 10).

Dynamic tests on the vehicle are not required, since the dimensions fall within the measurements set by the manufacturer.

Manufacturing: materials (metallurgical analysis and subsequent mechanical characteristics), corrosion test, rotating bending test, rolling test, impact test, alternating torque test.

Vehicle fitment: documentation/information on the characteristics of the wheel, vehicle model and fitting instruction details, wheel caliper checks, ventilation hole checks, wheel fixing.


Given the non-mandatory scope of the UNECE 124 regulation, the situation "prior to the decree" allowed the marketing of replacement wheels without any authorization and relative checks, while fitting "Special wheels" with tires of different sizes, diameters and sections, was subordinate to the technical go-ahead of the vehicle manufacturer.

The need of a regulation, effective after the issue of the Decreto Ruote 20/2013, was dictated by:

• the commitment to safeguard traffic safety, prescribing mandatory approvals for all replacement wheels (excluding of course those provided by the vehicle manufacturer), to prevent the marketing of products with lower safety standards already introduced following the UNECE 124 regulation.

• furthermore, the opportunity to approve “special wheels” (not possible under the UNECE 124 regulation) introducing a national approval scheme with specific rules and limitations.


National approval - NAD

Wheel with national NAD approvals.


This is issued by the competent 3rd Dept. of the DVLA Directorate General on the basis of positive test results, carried out by a test center or by the DVLA’s Technical Service, following the request from a manufacturer or representative, of the wheel unit.

Besides meeting the general requirements, wheels are required to submit to tests /trials provided by the UNECE 124 regulation.

Special wheels must undergo static and dynamic tests, with the wheel/tire unit fitted on a vehicle typical of the class it is destined for.

Static tests verify that enough safety space is guaranteed with other elements of the vehicle (possible interference). The regulation specifies, for example, the wheel track variation allowed.

Dynamic tests (where necessary) are developed as follows:

-Overall dimension test (external cross-section to the original);

-Road handling (program subject to approval by the technical service);

-ABS braking test (if the offset is different from the original);

-moose test (in case tire sizes are different from those already approved).

The assigned approval number, following the tests and the submission of the relevant documentation, is made up of seven characters, the first three are “NAD”, followed by a capital letter which indicates the year of issue (from D to Y for years going from 2013 to 2030) and three alphanumerical characters indicating the basic approval. The number must be marked on each wheel so as to be permanent and readable even when the wheel is fitted.


Approval recognition by other Countries                       

So far approvals implemented in other countries cannot be recognized automatically. The legal framework, and the related technical regulations, do not quite match up to our legal system.

As far as wheel systems approved in other EU member states, an inspection is expected on the basis of any certification issued by a competent authority for approval. If the performed tests are equivalent to those required, it is not necessary to repeat the inspections. Reports, though, must still be validated by the competent authority, to have any official value. The test center or the DVLA technical service Centre will examine the request for recognition presented according to procedures.


Starting the 1st of October,  all wheels marketed as replacements (except those supplied by the vehicle manufacturer) will have to meet the requirements set in the Decreto 20 : ECE R124 approval (where sufficient) or the National NAD approval (i.e.  special wheels ). 

Each “wheel system” (single wheel, plus a tire and any necessary accessory) must be accompanied by a numbered compliance certificate, issued by the manufacturer according to the Decree’s annex D. The manufacturer must provide the relevant fitting instructions, which supply:

- correct fitting instruction details;

- compatibility check for the single vehicle;

- necessary recommendations.

The wheel fitment must be performed by an authorized workshop under the decree regulating vehicle repair and maintenance (Law Decree 122/92), which will issue a statement in accordance with the Decree’s Annex E. No changes to fenders, wheel arches, or the use of additional wheel arch flares are allowed, unless already provided for (alternative / optional), and approved  by the vehicle manufacturer.


Vehicle Registration Certificate                                          

On the vehicle registration certificate, the tire’s approval characteristics are recorded: size, speed and load index.

If the wheel system adopted falls within the size range already provided for in the vehicle approval there is no need for an upgrade: it is enough to keep in the vehicle both the certificate of conformity and the declaration of the installer.

If the wheel system adopts tire sizes other than those shown on the original registration certificate, this must be updated (art.78 of the Highway Code) at the nearest competent DVLA office, attaching the two documents mentioned above (Annex D and E) to the applicati


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