Green NCAP returns with revamped rating scheme and fresh results

Green NCAP released the results of 24 cars that have undergone its rigorous tests.

The electric cars stand out as the cleanest and most efficient vehicles but there are also big differences between the best and worst performing conventionally-powered cars.

By combining accurate measurements from extended laboratory testing with relevant real-world driving tests, Green NCAP ratings already offer the best of both worlds in terms of evaluation. The rating scheme now adds the assessment of greenhouse gases to those of clean air and energy efficiency, providing even more broad and comprehensive information for consumers.

The two electric cars tested in this round - the Hyundai KONA and Renault ZOE - both achieve a maximum five-star rating, with top marks for clean air, energy efficiency and greenhouse gases. Next in line is the Toyota C-HR with three and a half stars. The Toyota improves efficiency by utilising hybrid technology alongside its petrol engine and does so to better effect than the similarly-powered Honda CR-V which is awarded two and a half stars.

The three popular superminis - the VW Polo, Renault Clio and Peugeot 208 - are all rated as three-star vehicles. At the other end of the scale, the large people-carriers - VW Transporter, Mercedes-Benz V-Class and Opel Zafira - get no better than one and a half stars, mainly because of their weight and poorer aerodynamics. While very effective after-treatment means they control pollutant emissions well, they require a lot of energy - fuel - to move their weight around. The SUVs emerge little better than the vans with, on average, just over two stars.

In the large family car class, the Mercedes-Benz C220d gets three stars while the BMW 320d and VW Passat 2.0 TDI get two and a half stars apiece. The Mercedes, in particular, impressed with its control of pollutant emissions which, while nowhere near the zero tailpipe emissions of electric cars, nevertheless demonstrated what can be done with good engine design and exhaust after-treatment.

The revised rating scheme accords well with the sentiments expressed in a comprehensive European consumer survey, the full results of which will be published early next year.

Niels Jacobsen, CEO of International Consumer Research and Testing and President of Euro NCAP, said, “I'm proud that Green NCAP can now share the most comprehensive, in-depth rating on the environmental impact of new cars to help consumers make sustainable vehicle choices. Green NCAP's rating scheme has been comprehensively overhauled and now also includes an evaluation of Greenhouse Gas Emissions as well as Clean Air and Energy Efficiency. As we measure only tailpipe emissions, electric cars naturally come out best in this round of assessments.”

“However, Green NCAP will continue to evolve and we plan to include well-to-wheel emission measures and, ultimately, life-cycle analysis as a baseline for future ratings. With our current ratings, hybrid cars have obvious opportunities to score better than non-hybrids, but they don't always do that as manufacturers may decide to reduce costs by omitting simple but effective exhaust after-treatment devices such as particulate filters. Such lost opportunities are revealing and disheartening. Among combustion engine cars, the best performers are smaller cars, mounted with effective exhaust after-treatment where hybrid technology can give them an extra notch up in the ratings,” Jacobsen added.

All of the tests in this publication were sponsored by the European Commission as part of the Green Vehicle Index (GVI) project. Eric Cerneaz of the Innovation and Networks Executive Agency (INEA) and Project Officer for GVI, said, “Despite the complexity resulting from various vehicle propulsion technologies and difficulties caused by the current pandemic, GVI has delivered a new holistic methodology based on a great amount of testing and data collection. We are happy to see published this first set of results and we are sure that the work done represents a first important step in the development of a widely accepted green vehicle index that will support informed consumer choice and will contribute to a more sustainable future”.

No plug-in hybrids were included in this round of tests but the first will be included the next round, expected in February of next year. Going forward, Green NCAP plans to further extend its analysis from ‘tank to wheel' to ‘well to wheel' and take account of the ‘upstream' emissions involved in the manufacture of fuels or in the generation of electricity.

For the time being, the Green NCAP's 2020 ratings are still based on ‘tank to wheel' even though the recent update to the methodology and inclusion of new measurements means that the ratings are significantly different to those published in 2019 and should not be compared.