Miljøprojekt, 888 – Chiptuning af køretøjer - miljømæssig effekt

Electronic Tampering of Vehicles - Environmental Impacts

Summary and conclusions

This report describes a project with the objective to investigate the environmental effect caused by electronic tampering of the engine control systems in new vehicles. The Danish Technological Institute was responsible for the investigation, and the project was financed by the Danish Environmental Protection Agency.

The objective of the project was to determine the extent of electronically tampered vehicles in Denmark and to evaluate the environmental effect caused by this kind of tampering. In addition, legislation regarding the issue was examined.

The investigation was limited to diesel-powered passenger cars, light-duty vehicles and heavy-duty vehicles. No measurements were carried out in this project, but test results from previous investigations are included.

Unfortunately, it has not been possible to determine the number of electronically tampered vehicles in Denmark. The investigation shows that the companies and individuals selling tampering devices are very reluctant to pass on information about their sales figures. The investigation also shows that there is a large supply of tampering devices from both Danish and foreign suppliers on the Internet. It is not possible to determine the number of devices bought in that way.

An earlier estimate of the numbers of tampered diesel-powered vehicles in Denmark indicates that somewhere between every third an every second new diesel-powered passenger car is tampered. This estimate is still considered to be realistic, but it cannot be verified by this investigation.

The emission test results from tampered diesel-powered vehicles show that the emissions depend strongly on how the vehicle is used. If the engine is exposed to moderate loads, the emissions do not increase considerably. If, on the other hand, the engine is exposed to high loads, the emissions increase drastically. In some cases the emissions of particulates increase by several hundred per cent.

The test cycle used for type approval of passenger cars does not include very high loads, as the vehicle speed is moderate during most of the cycle, and does not exceed 120 km/h. Similarly, the periodical inspections only include a no-load free acceleration. However, some of the best tampering devices can be approved in these tests, despite the fact that they show some very poor environmental behaviour when they are exposed to higher loads.

Since the investigation shows that the most important parameter is the individual driving profile - which is unknown - and that the number of tampered cars is uncertain, it is not possible to determine the absolute environmental effect caused by electronic tampering of diesel vehicles.

However, it must be expected that tampering will have a considerable impact on the environment, since the investigation shows that at high loads a tampered car causes a considerable emission.