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AIR Index is a standardised motor vehicle emissions ranking system introduced in February 2019 by Allow Independent Road-testing (AIR). The objective of the system is to encourage the use of independent and meaningful motor vehicle NOx emissions tests to robustly inform consumers and policymakers of the real-world impact motor vehicles will have on urban air quality.



AIR, the United Kingdom-based group behind the index, is an alliance of scientists, academics and economists from public and private organisations and is a not-for-profit organisation.[1][2][3] The alliance aims to provide independent and rigorous data that will help consumers and policymakers reduce the negative impact that motor vehicles have on urban air quality.[2] Nick Molden, one of the co-founders of AIR, said: "The transparent publication of independent, on-road emissions testing results is the most efficient way to improve air quality."[2] Another co-founder Massimo Fedeli said: "It gives easy to understand, at-a-glance information on actual vehicle emissions in towns and cities."[4] The ambition for the founders of AIR is that their AIR Index scheme will have a similar impact on real-world vehicle emissions as the Euro NCAP scheme has on real-world vehicle safety.[4]

Vehicle testing and rankingEdit

The AIR Index gives individual vehicle models an A, B, C, D or E rating, and correspondingly colour-coded as green, yellow-green, yellow, amber or red (in a similar way to the European Union energy label system used for domestic appliances).[5][3] The rankings are based on the nitrogen oxide (NOx) emissions of the vehicle, independently measured in a standardised way, and on at least two independently sourced vehicles, with a portable emissions measurement system (PEMS) in real-world urban driving situations.[5][4][3]

The rating is based on the number of milligrams per kilometre (mg/km) of NOx emitted as follows: A (green) = 0-80, B (yellow-green) = 80-168, C (yellow) = 168-270, D (amber) = 270-600 and E (red) = 600 and above.[5]

The ratings of six Euro 6 compliant cars were published at the time the AIR Index scheme was launched.[4]

The first six AIR Index ratings
Model Year Fuel AIR Index
Land Rover Discovery 3.0 TD6 2018 Diesel A
Nissan Qashqai 1.2 DiG-T 2017 Petrol B
Mini Cooper SD 2015 Diesel C
Dacia Duster 1.5 dCi 2018 Diesel D
Ford Focus 1.5 TDCi 2017 Diesel D
Renault Clio 1.5 dCi 2017 Diesel E


The leader of the West Virginia University team that discovered some of the early evidence of the Volkswagen Dieselgate scandal, Dan Carder, director of their Center for Alternative Fuels, Engines and Emissions, said: "If the AIR Index had been implemented 15 years ago, Dieselgate would likely not have happened."[5]


In March 2019, Jaguar Land Rover (JLR) became the first European car producer to submit new cars from its marques for testing.[6]

New JLR car ratings (Euro 6 allows up to 80 mg/km NOx emission)
Model Year Fuel NOx
AIR Index
Jaguar E-Pace HSE 2.0I 180hp 2019 Diesel 14 A
Land Rover Range Rover Evoque TD4 2.0I 180hp 2019 Diesel 17 A
Land Rover Discovery 3.0 TD6 HSE 2018 Diesel 33 A
Land Rover Discovery Sport 2.0I 180hp 2019 Diesel 34 A

See alsoEdit


  1. ^ "Contact Us". AIR. Retrieved 7 March 2019.
  2. ^ a b c Ogden, Chris (28 February 2019). "AIR alliance launches new vehicle emissions ranking system". Retrieved 7 March 2019.
  3. ^ a b c "Air Index launches on-road, independent guide to tailpipe emissions". FleetNews. 28 February 2019. Retrieved 7 March 2019.
  4. ^ a b c d Aucock, Richard (28 February 2019). "Land Rover excels in new car NOx emissions AIR index – but Renault slammed". Motoring Research. Retrieved 7 March 2019.
  5. ^ a b c d Shale-Hester, Tristan (28 February 2019). "New AIR Index car emissions system launches with red, amber and green ratings". AutoExpress. Retrieved 7 March 2019.
  6. ^ "JLR tests new cars with AIR index, new diesel engines among cleanest for NOx emissions". Professional Autocar. 7 March 2019. Retrieved 7 March 2019.

External linksEdit