WEBVTT
Vehicles with combustion engines generate emissions. For this legal limits apply. Compliance with these limits according with the standardised WLTP method is now being tested on a dynamometer. As of September 2017, Nitrogen oxides and the number soot particles are also measured on public roads in Germany and the EU using the real driving emission test or RDE for short. In this test emissions are measured using the portable emissions measurement system PEMS. During these trials, real influencing factors influence the vehicle including ambient temperature, altitude, gradients and slopes, headwind and tail wind. A personal driving style any cargo being transported and the use of electrical consumers such as air conditioning system are factored into measuring results. The test route can be chosen almost completely freely as long as it takes you through the city, overland, and over the motorway for at least 16 kilometres each. An RDE trial run may last between 1.5 and 2 hours. This means that RDE is able to cover a range of different personal driving profiles and styles. Measurements start in the city with a cold start. Since a cold engine produces more emissions. It’s the same for stop and go traffic. On country roads the vehicle travels between 60 and 90 km/h. Even faster on the motorway reaching 145km/h or even reaching 160km/h for short bursts. Due to these disparities between different applicable routes the results are not comparable. The subsequent emissions analysis checks whether the limits have been complied with. For nitrogen oxides there is a conformity factor of 2.1. Which means that emissions on the road are permitted to be twice as high at a maximum as those on the dynamometer. From 2020 the same limit values will apply as in the laboratory. Only measurement tolerances will be granted a concession of 50%. The same is applied to the number of soot particles since September 2017. This will mean that there are no differences between the vehicle emissions. The RDE test ensures that emissions of vehicles on the dynamometer and in everyday driving are widely matching. Real Driving Emissions.