41.Before a new vehicle is licensed for sale in the EU, a manufacturer must demonstrate in laboratory tests that the model emits less than a set level of key pollutants, including NOx and particulates. These limits are set under a ‘Euro’ regime, in place since 1992. Limits are revised periodically and standards for the latest vehicles (Euro 6) have tightened considerably. They may emit only a small fraction of pollutants permitted under the 1992 ‘Euro 1’ standards. Limits have tightened since the previous 2011 (Euro 5) standards: for example, diesel vehicles must emit 56% less NOx.
42.However, there are long-standing concerns that EU laboratory tests significantly under-estimate emissions on the road. This has meant Member States’ plans to meet EU NO₂ limits have been thrown off course since they assumed much higher reductions in emissions from the newer vehicles licensed under tougher standards than have been achieved in practice. Prolonged discussions between the EU and the automotive industry on introducing better tests were given impetus following US regulators’ discovery in 2015 that Volkswagen (VW) had been fitting vehicles with illegal software (‘defeat devices’) to enable vehicles to pass laboratory tests. However, manufacturers have in any case been able to use legal means to prepare vehicles to pass the tests even though their performance would not then be replicated on the road in a consistent manner. To date only VW has been identified as using illegal methods, but disparities between laboratory and real world emissions from other manufacturers’ vehicles have also consistently proved considerable. On average across all makes of vehicle, emissions on the road are 400% higher than those measured in the lab under EU tests.
43.The EU is introducing new real-world tests from 2017. Commentators have criticised the EU for setting initial limits under the new tests which are twice as high as the previous laboratory test levels and for setting limits into the 2020s which are 50% higher.The EU proposals state that this is to allow for the less accurate measurements gathered by tail-pipe monitors under real-world as opposed to laboratory conditions. However, as MEPs on the Brussels Environment Committee noted, the maximum discrepancy from the new method of measuring emissions is 30%.
44.Although Defra Minister Rory Stewart said that the UK had pushed since 2011 for real-world driving tests, witnesses were unconvinced about the Government’s commitment to securing lower EU limits. According to the Guardian, the UK Government supported a level 40% above current limits to apply even as far ahead as 2021.ClientEarth accused Ministers of “double speak”, in blaming the EU system for failing to reduce pollution whilst supporting less robust action from Brussels. Some MEPs and commentators such as the International Council on Clean Transport criticise EU institutions for, in their view, watering down final limits in response to lobbying from the automotive industry. However, witnesses such as VW told us that the automotive industry agreed that the emissions testing regime needed to be improved.
45.Although it has taken far too long to agree, we welcome the adoption of a new EU real-world vehicle testing regime since current laboratory tests have routinely and significantly under-estimated emission levels. However, the new limits allow a generous leeway for measurement error and are set above current levels.
46.The UK Government must in future negotiations argue robustly for lower EU limits which will deliver reductions on the road equal to, or better than, current laboratory limits. Tougher limits are needed to drive urgent action by the automotive industry to both improve monitoring and to reduce emissions as fast as technically possible.
47.Uncertainty over the content and timing of the future EU emissions regime led witnesses to question the validity of the models Defra used to develop its NO₂ proposals. The Environmental Protection Association considered emissions models were based on over-optimistic assumptions, and Gatwick Airport told us that the Government model “systematically” under-estimated emissions. The LGA recommended that Defra remodel its data to reflect real-world emissions levels. In contrast the GLA noted that, although Euro 6 standards had not been in place long enough to produce a mass of real-world emissions data, Defra should have been able to apply correction factors to the laboratory results from a database of ‘real world’ emissions results. Defra said that it adopted caution in its assessment of the emissions levels which would be achieved in practice under new EU standards.
48.We note that Defra models are based on cautious assumptions about the extent to which the new EU vehicle testing regime would deliver NO₂ reductions on the road. However, a history of failure to translate theoretical standards into cleaner air in practice means that Defra must keep its assumptions under review.
49.We recommend that Defra publishes: first, by the end of 2016 an analysis of the impact on UK air quality of Euro 6 vehicle emissions standards; and secondly, by the end of 2018, an analysis of the impact of new real-world driving emissions tests being introduced from 2017. Should either of these reports show that EU standards are in practice failing to have the impact assumed under current plans, Defra must issue revised plans including stronger measures to tackle vehicle emissions.
50.We asked VW whether its use of so-called ‘defeat devices’ to cheat EU emission tests had affected individual vehicle performance or pollution levels. VW apologised for its actions but argued that the use of the devices did not affect on-the-road NOx emissions, or fuel consumption so compensation was not warranted. Compensation is the subject of complex legal discussion in various countries including the US where, unlike in the UK, the company is giving customers vouchers as a goodwill gesture. Paul Willis, VW UK’s Managing Director, failed to answer many of the questions we put to him during an oral evidence session in January 2016, explaining that he was awaiting the outcome of a company review of events. The EU is conducting a separate inquiry into the use of defeat devices and wider problems with the emissions testing regime, to report within a year.
51.Commentators link VW’s use of illegal software to wider concerns about whether consumers are being misled by manufacturers’ claims about their vehicles’ emissions and performance. Press coverage of research published in February 2016 highlighted the significant discrepancy in the amounts of CO₂ emitted on the road by a range of manufacturers’ vehicles compared to marketing claims.
52.Volkswagen’s use of illegal devices has rightly caused consumers to be sceptical about its claims on vehicle performance. The company’s different treatment of UK and US customers is also unlikely to be seen as fair. Volkswagen’s evidence did not persuade us that the company had fully learnt lessons about the need to be completely transparent if it is to regain customers’ trust in its products.
53.The Government must assess whether systems are sufficiently rigorous to give customers confidence that a claim about a vehicle’s performance is true. Where proven to have misled customers, the company should pay appropriate compensation. The Government must act on the findings of the EU’s review of emissions testing and the outcome of Volkswagen’s review of its use of defeat devices to remedy any deficiencies in consumer protection regulation. The Government must also seek at a European level a review of the penalties applicable if deliberately cheating the emissions testing system, and work to ensure that these penalties are robust enough to provide a meaningful deterrent for manufacturers.
63 There is a parallel Euro regime for heavier vehicles.
64 Society of Motor Manufacturers and Traders, Euro-6 What is it? accessed 11 April 2016
65 “”, Air Quality News, 28 October 2015
66 As above
67 “”, European Parliament News, 14 December 2015
68 Evidence by Rory Stewart MP to Environmental Audit Committee inquiry into Diesel emissions and air quality regulation, 27 October 2015, HC 506,
69 “” the Guardian, 13 December 2015
71 “” The Guardian, 28 October 2015
72 Volkswagen () para 15
73 Environmental Protection UK ()
74 Gatwick Airport Ltd ()
75 Local Government Association () para 3.9
76 Greater London Authority ()
79 “”, BBC News, 9 November 2015
81 “”, European Parliament News, 21 January 2016
82 “” ADI News, 17 February 2016
25 April 2016