The TRUE initiative seeks to supply cities with data regarding the real-world emissions of vehicle fleets, and equip them with technical information that can be used for strategic decision-making. One of the key objectives of TRUE is to raise awareness of the magnitude and scope of excessive real-world vehicle emissions.
The rating system is designed to concisely convey the relative magnitude of real-world emissions from Euro 3 through to Euro 6 vehicle models under a wide range of operating conditions and driving behaviors. Factors included in the ratings include emission control system deterioration, defective parts, software that increases emissions in conditions outside of those typically covered by the regulation, and improvements by recalls and retrofits.
The three-color TRUE rating system was developed as an easy-to-use tool for identifying the lowest and highest emitting vehicles in the fleet. The TRUE rating can help car owners know whether their car is clean and can help potential buyers identify the cleanest available cars for purchase (for NOx). The ratings represent, as best as is possible, measurements of real-world emissions.