Pass the ITV and Car Modification

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modified car

Sometimes when we buy a car, we think about modifying its appearance or performance in some way. Any car modifications should pass the ITV, so I am not referring to tuning, although it is included in these important reforms, to any modification, incorporation, suppression or a simple substitution in one or more of the parts of the car that implies a change in characteristics, or that modifies a data on the card ITV of the car.

In these cases, these modifications oblige us to fulfill a series of requirements, such as processing the corresponding reform. And then passing a technical inspection that gives us the go-ahead to be able to drive on any Spanish road. Only in those cases, complying with the “paperwork”, we can pass a subsequent ITV.

Spoilers, exclusive wheels, bold colors … Before embarking on any customization, we must fully understand what we can and cannot do. Eye-catching spoilers, prominent bumpers, exclusive wheels, colors that do not leave you indifferent, modifications to the suspensions, in the engine control unit, replacement of seats, the steering wheel … It is known as tuning, custom cars even to the extreme of being unique and unrecognizable.

The background of ITV

The explosion of car tuning began in the United States after the end of World War II, in the 1940s. Also in European countries such as Germany, the United Kingdom, or Italy, and Asia, China, or Japan. There are the biggest fans of modifying cars. Focusing on Spain, the golden age of tuning dates back to the 90s. But legislative restrictions and bureaucracy related to major vehicle reforms have ended the claims of many drivers. Even so, Spain has a large number of car tuning fans, who proudly boast at the wheel of their creations.

What is ITV?

Depending on the scope of the modifications, tuning has many hours of work and a lot of money behind it. So before starting any customization, we must well understand what we can do and what we can not do. That is to say it. Because in Spain the important vehicle reforms are regulated through Royal Decree DC866 / 2010, of July 2. His objective is to unify the criteria of Spanish legislation with the European one. The decree was accompanied by a vehicle reform manual prepared by the ministry of industry, tourism and commerce in cooperation with the autonomous community’s independent television authority.

The final revision of the manual took effect on January 1, 2017. It defines the standardized reforms, their codification, and accurate documentation for processing. And this why? Because there are certain changes in vehicles that require their approval by a competent body and the corresponding certification when passing the Technical Inspection of Vehicles.

As we have just said, we are not referring to tuning exclusively, which is largely aesthetic, but to reforms such as adapting a streetcar to competition (a local rally, for example). So we are talking about any project that has to do with “getting your hands on” the car. When adapting the car to the competition, not only do you have to successfully pass the ITV. And the driver must have the corresponding license. Otherwise, he could not drive (the car would not comply 100% with the RGC ).

What reforms can be done in the car? Are they approved?

A few months ago, the department of justice worked with autonomous communities to develop a new important vehicle reform manual. It details the types of reforms allowed. And It establishes the standards, procedures and requirements needed to address reform.  There are possible reforms for all types of vehicles, but we will focus on cars.

These are the types of possible reforms :


For example, the total or partial replacement of the frame or the self-supporting structure when the one that is replaced is the part that bears the identification number; the change of location of the registration place; the retroquelado.

2.Drive unit

For example, the modification or replacement of the elements of the intake system, the supply system, and the drive unit; changes to the exhaust system; any modification to the fuel tank; any modification in the switchboard …


Modifying the clutch system, the gearbox, or modifying the number of drive axles, among other things.

4.Axles and wheels

Modify the number of axles, the distance between them, or mount non-equivalent tires.


Any modification to the suspensions or their elastic elements.


Modification of the steering system, the location of the steering wheel, the replacement of the steering wheel by another, …


Change the characteristics of the braking system. Install or uninstall auxiliary kinetic energy absorption systems. Modify the brake controls and their location, among other things.


The most extensive section in complexity and variety of conditions.Among many others: changes in seats, in seat belts, conditioning of space for the installation of wheelchairs, body modifications …

9.Lighting and signaling devices

Here comes any modification or replacement.

10.Connections between towing vehicles and their trailers or semi-trailers

11.Modifications of the data that appear on the ITV card

For example the variation of the MMA or the modification of the vehicle for competition.

What documentation should I provide when I make major reforms?-Go to ITV

When significant modifications or alterations are made to the vehicle, as reflected in the previous category, the owner of the vehicle must provide certain documents, in addition to the fact that it is mandatory that, within 15 days, go to ITV.

By doing so, we will ensure that, first, we comply with the law. Secondly, the car meets all the stipulated safety requirements. The vehicle reform manual is very clear with the necessary documentation, as we can see:

  • Technical project and final certification of work. In other words, it is necessary to prepare a report. Describe in detail the objectives of the reform, who will do it, and on what tools (including all relevant details).There is no need to do so if the reforms undertaken are in an approved type.
  • Final construction management certificate.
  • If the process involves several reforms, each one will be identified with the code detailed in the manual.
  • Provide the Certificate of the workshop in which the reform.

What is considered important reform in the vehicle?

If you add elements to a car that imply a change in its physical dimensions. Or if you assemble tires that are not approved for use in the car, you will have no choice. Only go to ITV with the proper approval and authorization. Otherwise said vehicle will be prohibited from moving, and this section includes balls or trailer hitches.

It also requires approval and documentation for tinted Windows, changing shock absorbers for other unapproved vehicles. Modify the exhaust system, or the engine control unit to increase power. Any item that affects the identification of the vehicle, or to modify the information that appears on the ITV card. For example, the drive unit, transmission, axles, suspension, steering, brakes, bodywork, lighting and signaling devices.

After any modification, the owner must go through the ITV. Within 15 days and take with him the detailed technical project of the reform. The conformity report issued by a technical reform service or by the vehicle manufacturer itself. And the certificate of the workshop that carried out said modification. Besides, all the reforms carried out must be noted on the ITV Card.

Regarding window tinting, it requires documentation that must always accompany the technical sheet. The approval certificate issued by the sheet manufacturer completed by the installation workshop. Neither the front doors nor the windshield can be tinted. And all the treated windows must be sealed by marks with sand guns, stickers, or legends on the sheet itself. If these specifications are not met, the ITV will not be favorable and could carry a fine.

As for the chassis

It is again a complicated section. In principle, you can choose a stronger or softer shock absorber than the original, provided that it fits our model. Even so, once installed, it will need to carry an assembly certificate and a diagnostic certificate through the ITV. It must be clear that the height of the car or its hardness will hardly change. If you want to alter them, you will have to go to an engineer to study the feasibility of the reform, and in a favorable case pay your report (not less than 200 euros, parts on the sidelines) before passing the ITV.

As for the engine

Some manufacturers offer intake kits that win a horse. In exchange, to have a complete exhaust line, which also improves power, a technical project is necessary, again drawn up by an engineer. The direct installation of a high flow filter or power chip is inconsistent, which will always change the consumer value and , consequently, emissions.

What can you change from your vehicle to pass the ITV without problems?


If you do not want to have unpleasant surprises when passing the ITV, such as the one that your vehicle will throw you back because it does not meet the manufacturer’s approval requirements. It is higly recommended that you inform yourself well about what elements you can change without problems to pass the ITV and what modifications require ‘paperwork’ to obtain approval. Almost all changes related to the passenger compartment of the car can be made without requesting your authorization: changing the sound system, the upholstery of the seats

On the other hand, if you want to replace the steering wheel or seats, you must provide the necessary documentation. These reforms affect the direction and safety of the vehicle.You will also have no problem if you change the paint of the bodywork or the rims or tires of the vehicle, as long as the chosen size is in the list of measures approved by the manufacturer that appears on the technical inspection card. In the same way you can modify the exterior aesthetics as long as it does not imply a modification of the vehicle measurements.

Quality comes from professional pursuit

front grill

Now let us consider the modification of Monster Upper Grill Fit For Ford F-150 2015 2016 2017 w/3 Head LED Lights Material: ABS plastic. No drilling-easy installtrion; New Rear Bumper Diffuser Fits 2015-2019 Dodge Charger SRT OE Style PP Splitter; Chrome Grille Overlay Snap On Insert Fits For 2016-2018 Chevy Silverado 1500…These are all legal modifications and can pass the ITV without  problems.

modified race car

4 modifications in your car with which you will not be able to pass the ITV

We all like that our vehicle reflects our personality, after all, for many the car is more than just a mobility tool. That is why modifications are the order of the day. However, there are modifications that we cannot simply make and forget, since they are illegal for ITV purposes, and we cannot overcome it with them. Here are four modifications that you will not be able to apply to your car if you want to pass the ITV:

1. Brakes

The braking system of your car is one of the most critical points. For this reason, the ITV does not admit, for example, that you change your smooth discs for others with perforations. It also does not allow to replace the standard brake hoses with other metallic ones. And for both modifications, you will have to approve, with the consequent cost. OR It cannot pass the ITV.

pass the ITV

2. Lighting

The installation of unauthorized lighting systems is one of the main reasons for rejecting vehicles on the ITV. So you cannot install xenon or LED bulbs if your car is shipped from the factory with halogen bulbs. In some cases, when we talk about xenon bulbs, you should change the entire headlight, install a headlight washer and an automatic light beam height regulator. Besides, brands such as Phillips offer lamps of higher power. It approved and marketed through specific distributors who provide the necessary documentation for pass the ITV.

How to pass ITV

3. Tires

Changing your car tires is not a bad idea if you improve its performance. However, you must respect the measures that the vehicle manufacturer approves for your car model. There is an equivalence principle that gives a 3% margin. But if you go beyond  3%, your tires will no longer be legal. It cannot pass the ITV.

old modified race car pictures

4. Steering wheel

Many people change the steering wheel of their car, because they argue that the serial steering wheel is too big or awkward to use. Generally, when the steering wheel is modified, the driver’s airbag is removed, which is completely illegal. It cannot pass the ITV.

modified stock car

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