Recent TNO rapports as annexes to letter of Ministry of Infrastructure and Water management to the Dutch Parliament

23 Jan 2020

The Ministry of Infrastructure and Water management has recently sent a letter to the Dutch Parliament with an update about Dieselgate in particular and more generally about the emissions of (diesel) vehicles. As annexes to that letter also three TNO reports have been sent to Parliament. In addition a fourth recent TNO report has been published that is relevant to developments with respect to emission legislation for passenger cars and vans.

For more information we refer you to the site of the Ministry of Infrastructure and Water Management

(in Dutch)

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Effects of a software update on a VW Polo

In response to a request from Parliament, the Dutch Ministry of Infrastructure and Water management has asked TNO to collect data on the consequences for real-world emissions and for vehicle owners of the software update that has been made available by Volkswagen for cars with a defeat device.

For one VW Polo from the group of cars containing defeat devices the emission behavior has been measured and analysed before and after application of a software update. The vehicle was monitored during a two year period. The software update was found to have hardly any impact on the NOx emissions, CO2 emissions and fuel consumption, and engine power.

Measurements for RDW on a Jeep Cherokee and Suzuki Vitara

On behalf of the Dutch road vehicle authority RDW, TNO has carried out emission investigations on a Euro 5a Jeep Cherokee and a Euro 6b Suzuki Vitara, both equipped with a diesel engine. Previous tests by RDW from 2017 yielded results that justified further investigations. The objective of the follow-up investigations carried out by TNO was to measure the NOx emission behavior of both vehicles before and after an update of the engine calibration software. Emission measurements have been carried out on a test track at the RDW facilities, on a chassis dynamometer and on public roads. For information on the interpretation of the results we refer to RDW.

Investigation into emissions outside the RDE boundaries

Test programmes, carried out by TNO over the last decades, have revealed that the real-world emissions of (mainly) diesel cars are generally much higher than the regulatory emission limits. Cars were found to be optimized on the official laboratory test, used for type approval. Under driving conditions not covered by this test manufacturers used alternative emission control strategies, generally motivated as needed to protect the engine. Since the addition to the type approval test procedure of a measurement on the road (so-called RDE or Real Driving Emissions) in 2017 this has changed: in real-world driving cars must now produce low emissions over a much wider range of driving conditions. But not all driving conditions are covered by the new RDE test. Striking examples are a family of five in a car packed with luggage and equipped with a roof box on their way to a holiday destination, cars towing trailers or caravans, and emissions from engines running stationary when the driver cleans the ice from the windows in winter. How high these emissions outside the RDE window are allowed to be, has not been sufficiently regulated yet. TNO has charted the relevant driving circumstances and has investigated the extent to which it is technically possible to demand low emissions also in these driving conditions. As part of the preparation of new European Euro-7 emission legislation, it is now discussed whether the RDE requirements can be extended.

Relevant reports

Our work

Measuring the emissions of passenger cars and vans

TNO has been commissioned by the Ministry of Infrastructure and the Environment to conduct an in-service testing programme for cars and vans. In the context of this multi-annual programme, TNO subjects... Read more
Our work

Improving air quality by monitoring real-world emissions

Measurements reveal that a gap has existed between official European emissions standards for vehicles and their actual emissions on the road for some time now. We have been measuring emissions of hazardous... Read more

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