What is The Real Urban Emissions Initiative?


The Real Urban Emissions Initiative (TRUE) supports cities worldwide to develop effective air quality and climate policies with independent real-world vehicle emissions data, technical analysis, and expert advice.


Who is part of the TRUE initiative?


The TRUE partners are:

The TRUE Initiative is also supported by an Advisory Group with members such as Transport and Environment (T&E), C40 Cities, Clean Air Fund, and several universities globally.


What are the objectives of the TRUE initiative?


TRUE’s objective is to inform policymakers, manufacturers, and consumers of the impact of vehicle emissions on air quality through good data, transparency, and technical expertise.

What is the TRUE rating system?


TRUE uses a methodology developed by the ICCT to create a “traffic light” rating system which ranks cars based on their real-world nitrous oxide (NOx) exhaust emissions. Green is a ‘good’ rating, yellow is ‘moderate’ and red means that a vehicle produces more than 180 mg/km of NOx and is ‘poor’.

Anyone with a European-registered vehicle can search for the TRUE rating of a car by make, model, engine displacement, fuel type, and Euro standard.

What data is TRUE using?


The TRUE rating system uses data collected across Europe. It contains measurements gathered as part of the CONOX, CARES and Air Remote Sensing Project projects, which were funded respectively by the Swiss Federal Office for the Environment, the European Commission and Transport Scotland, as well as data the TRUE initiative collected in London, Paris, Brussels and Warsaw. It is the largest collection of data on vehicles emissions in Europe to be brought together so far. The measurements of over 1.6 million individual cars from this data set have been used to create the TRUE ranking.

Further data from testing undertaken by TRUE in London and Paris will be added to the rating system in the future.

What does the data show?


The results confirm that real-world NOx emissions are systemically much higher from diesel cars. Most Euro 6 petrol cars received a ‘good’ or ‘moderate’ rating while only a small share of Euro 6 diesel car received a ‘good’ rating.

What about RDE compliant vehicles?


Our remote sensing tests shows that the latest RDE compliant vehicles (6d) perform better than earlier steps of the Euro 6 regulation, especially for diesel with a majority of ‘moderate’ rating. Still, only a small share of diesel received a green rating, when for petrol the majority did.