Q. What are the typical car NOx emissions? How do diesel cars compare with petrol?
Q. How do diesel / petrol cars perform against the EU NOx emissions standards? Q. What about by manufacturer? |
SOURCES
DEFRA (Department for Environment, Food & Rural Affairs). Consultation document on ‘Tackling nitrogen dioxide in our towns and cities’. Published May 2017. consult.defra.gov.uk/airquality/air-quality-plan-for-tackling-nitrogen-dioxide For Manufacturers' average car NOx emissions: TRUE - The real urban emissions initiative. Report on ‘Determination of real-world emissions from passenger vehicles using remote sensing data’. June 2018. The graph data is not publicly available but was kindly provided by ICCT. The associated report can be viewed here: www.trueinitiative.org/data/publications/determination-of-real-world-emissions-from-passenger-vehicles-using-remote-sensing-data |
NOx Emissions by Fuel Type
Since 2000, the EU have been setting car emission 'standards' or targets which the automotive industry were expected to achieve, including Nitrogen Oxide (NOx). Diesel cars have consistently been above the target, by a considerable margin. Whereas petrol cars were initially above the target but have improved and since 2009, have been in line with the target. |
As a percentage difference to the target, diesel cars have been growing further away with each update from the EU - with the most recent difference at around 650% more than the target (2014). On the other hand, petrol cars' NOx emissions were initially above the targeted limit (2000 and 2005) but have been below or in line with the target since 2009. |
NOx Emissions by Manufacturer
In June 2018, a collaborative initiative called 'TRUE' published a paper on real-world NOx emissions. The paper details the use of remote sensing data to estimate on-road NOx emissions from diesel and petrol cars in Europe. For petrol cars, 8 manufacturers were achieving the EU target (47%), while 9 were not (53%). The best performing were Honda, Jaguar Land Rover, and Toyota, with NOx emissions below the target limit by 43% to 53%. However for diesel cars, 100% of manufacturers were significantly above the EU target (i.e. at least 100% more). The worst performing were Suzuki, Sabaru and Renault-Nissan, with NOx emissions between 1,119% to 1,416% above the target limit. |
Total NOx Emissions Breakdown
In 2016, cars represented 17% of the total NOx emissions in the UK. The largest contributors were 'combustion in industry' (32%) and 'other transport' (30%). Since 1970, the total NOx emissions from cars increased to a peak in 1990 of around 125% more. Then there was a significant drop up to around 2009, wher it has levelled out a bit. In 2017, the total car NOx emissions were approximately 60% lower than the baseline year (1970), and a similar trend is seen in 'other tranpsort' and 'heavy duty vehicles'. |