After EuroNCAP, Green NCAP. While the first is dedicated to evaluating how safe the models on the market are, the second (recently created) aims to assess the environmental performance of automobiles.
In its most recent round of tests, Green NCAP evaluated five models, which are based on two indices: Clean Air Index and Energy Efficiency Index.
The first evaluates the car's performance in mitigating pollutant emissions, giving it a rating from 0 to 10. The second also assigns a score from 0 to 10 based on its efficiency, that is, the ability to convert energy to boost the vehicle, wasting as little as possible. Finally, the overall assessment consists of a summary of the two assessment indices.
Diesel at the level of an electric in emissions?!
Mercedes-Benz C220d 4MATIC, Renault Scénic dCi 150, Audi A4 Avant g-tron (the first GNC model to be tested), Opel Corsa 1.0 (still made by GM generation) and Nissan Leaf. These were the five models put to the test and the truth is that there were some surprises.Subscribe to our newsletter
In terms of overall rating, the Leaf won out, as expected, earning a total of five stars (just as the BMW i3 and Hyundai Ioniq Electric had done before it).
Electric cars have an obvious advantage when it comes to the emission of pollutants (Clean Air Index) — they do not emit anything, as there is no combustion. And when it comes to efficiency, electric motors are far more efficient than any internal combustion engine — efficiency levels above 80% is the norm (already surpassing 90% in many cases), while best combustion engines are around 40%.
However, despite the mission impossible of one of the tested models with an internal combustion engine equaling the Leaf's five stars, there was a surprise when we looked at the Clean Air Index scores. For the first time, a non-electric model, the Mercedes-Benz C 220 d 4MATIC, achieved a rating of 10 points out of a possible 10, equaling the Nissan Leaf — yes, a Diesel car equaled an electric...
How is this possible?
Obviously, C 220 d emits polluting gases, there is combustion of diesel, therefore there is generation of harmful gases.
However, in the evaluation of this index, the German model presented pollutant gas emissions below the limit defined by the Green NCAP test — a test that starts from the WLTP, but which changes some parameters (for example, the ambient temperature at which it is carried out), to bring you even closer to real driving conditions.
Result: the Mercedes-Benz C 220 d 4MATIC achieved maximum scores for all emissions measured in the Clean Air Index, below the values stipulated by the Green NCAP.
This demonstrates that the most recent Diesels, which comply with the demanding Euro 6d-TEMP standard, equipped with efficient particulate filters and selective catalytic reduction (SCR) systems capable of eliminating the majority of nitrogen oxides (NOx) emissions, do not need to be stigmatized, according to Green NCAP.
However, in the overall ranking, the C 220 d 4MATIC was harmed by the results obtained in the Energy Efficiency Index (it was 5.3 out of 10), ending up with an overall three-star rating.
In the remaining models tested, the Corsa ended up with four stars, with the Scénic and the A4 G-Tron (this one still only complies with the Euro 6b standard) equaling the three stars of the C-Class.