The 1.6-liter Renault Espace diesel is the latest vehicle to come in the emissions crosshairs of German environmental NGO Deutsche Umwelthilfe (DUH). DUH published results of emissions testing by the University of Bern showing that NOx emissions from New European Driving Cycle (NEDC) driven tests with a warm engine exceed the applicable limit for Euro 6 vehicles 13- to 25-fold.
Renault immediately issued a statement disputing the Umwelthilfe findings, and asserted that Espace complies with applicable regulations, just as do all Renault vehicles.
|NEDC results (raw results without deterioration factor). Euro 6 limit is 80 mg/km. Source: DUH, University of Bern. Click to enlarge.|
The report from the University of Bern says 9 cycles were driven on the dyno with the Renault Espace, 8 of them NEDC. The NEDC measurements differed mainly with regard to the vehicle condition (cold or hot) and the preconditioning (1 x NEDC or 3 x EUDC).
During the tests, the following conditions were changed:
Measurements were performed with cold and warm engine states.
Before each NEDC measured, either one NEDC or three repetitions of the extra-urban part of the NEDC (EUDC) was driven. In order to measure the NEDC cold, the vehicle was conditioned the day before.
The roller dynamometer can be operated in two different modes: 2WD or 4WD. In the 4- wheel drive mode (4WD), the rear wheels rotate at the same speed as the front wheels. In 2-wheel drive mode (2WD), the two rear wheels are stationary. In both modes, the load is on the front axle and identical.
In addition to the NEDC cycle, the University of Bern team used a custom cycle specified by DUH. This cycle starts with three low-speed levels. In the process, the velocities of 20, 35 and 45 km/h were kept constant for 5 minutes each time. The speed is then accelerated to the final speed of 150 km/h with the same constant acceleration as shown in cycle 1. This speed is maintained for 120 seconds. The speed is, however, reduced analogously to the starting procedure but in reverse order, with the same speeds levels.
The measured NOx values of 6 NEDC cycles exceeded the Euro 6 limit of 80 mg/km by significant amounts: up to 2061 mg/km in the worst case. Two tests showed values lower than 80 mg/km.
Renault said that the test procedures used by the University of Bern are not all compliant with European regulations. The report shows important variations in test findings which are not conclusive and require “additional measurements”, the company added.
Renault also said it is endeavoring to understand the tests in detail especially in light of the findings published in August 2015 by the independent German institute ADAC which tested the Espace model and concluded that it complied with regulations.
DUH has filed enforcement actions against German cities in which NO2 limits are exceeded persistently. The DUH calls for, among other things, prohibiting the entry of diesel vehicles as long as there is no evidence that these comply with the applicable Euro emission limits.