WRITTEN QUESTION E-1978/01

by Juan Naranjo Escobar (PPE-DE) to the Commission

(5 July 2001)

Subject: New tests for emissions of pollutant gases

The new tests used to measure emissions of pollutant gases by diesel vehicles, whereby cars must accelerate at levels that may exceed those recommended by the manufacturer, are resulting

in damage to vehicles. These tests are carried out in accordance with a directive that stipulates that a car's exhaust pipe must be purged by a minimum of three cycles of no-load acceleration or an equivalent method. To carry out these tests, cars accelerate while stationary to 5 000 or 5 500 revolutions per minute, despite the fact that manufacturers recommend not exceeding 2 200 revolutions.

In view of this situation, the European automobile association has called on the Commission to modify the current rules, which disadvantage vehicle owners and compromise the reputation and good practice of the vehicle inspection centres which, in the final instance, assume responsibility for any damage caused while the tests are being carried out.

Bearing in mind the fact that sometimes, repeating the test two or three times is not sufficient to detect with certainty the level of emissions, which results in an even greater stress on the vehicle, does the Commission intend to take any action in response to the concerns raised by the European automobile association?

Answer given by Mrs de Palacio on behalf of the Commission

(6 September 2001)

Steady improvements in the emissions performance of motor vehicles have been made over the last decade, mainly as a result of improved engine technology and cleaner fuels and these improvements will continue for the future. As emission reduction technology evolves, the effectiveness of roadworthiness standards needs to ensure that the test procedures and standards are still capable of detecting gross emitters.

The aim of the roadworthiness test for vehicle emissions is to identify motor vehicles that are gross polluters, i.e. pollute at levels significantly in excess of prescribed limits. The roadworthiness test for smoke opacity needs to be relatively quick, simple and cheap to perform. Its aim is not to attempt to replicate real world conditions but to identify vehicles that are poorly maintained.

Diesel vehicles need to be tested for the opacity of the generated exhaust smoke during a transient, free acceleration engine test where the engine is accelerated against its own inertia. The test first became mandatory from 1 January 1996(1).

However, some Member States that carry out the diesel smoke opacity test have faced the problem of engine failure. Engines can fail if they are grossly inadequately maintained and if the engine is not sufficiently pre-conditioned, i.e. the test is conducted from a cold start.

With these problems in mind, the Commission tasked the International Vehicle Inspection Committee (CITA) to refine the method of testing and inspection. Based on the experiences that their members had with inadequate testing repeatability and engine failures, CITA proposed a revised testing procedure that introduced control to the rate of engine acceleration and included a preconditioning criterion to ensure the engine was sufficiently warm before testing commenced. These recommendations were incorporated in an amending directive(2), which has recently come into effect.

Consequently, testing authorities will need to train testers on how to comply with the Directive's provisions, in particular regarding the initial engine assessment (to ensure that the engine has no obvious fault that could render it vulnerable to failure in the test), the minimum pre-conditioning temperature and the rate of application of the engine's accelerator.

As has happened to modern petrol driven vehicles, new diesel passenger cars are to be equipped with on-board diagnostic (OBD) systems from 2003 and OBD systems will be required for light commercial vehicules from 2005. The OBD system will monitor the functioning of the emission control system and once equipped, the OBD system may well provide a cost-effective alternative to physical testing of the diesel. The Commission is currently carrying out work on how best to incorporate this benign technology into the roadworthiness test.

Nevertheless, in the interim and for the existing fleet, the currently required smoke opacity test is necessary to ensure that the gross polluters are identified and rectified as a condition for free circulation.

(1) Directive 92/55/EEC, OJ L 225, 10.8.1992.

(2) Directive 1999/52/EC, OJ L 142, 5.6.1999.