Emissions testing—keeping it clean

Following recent scandals in which car companies were found to be cheating regulated emissions tests and thousands of cars had to be recalled over their illegal polluting effects, the European Union has announced all new cars must pass stricter emissions tests from 1 September 2017. Gregory Jones QC, silk at Francis Taylor Building, analyses the likely effectiveness of the new EU car emissions test standards.

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What is the background leading up to introduction of the new emissions tests?

Heralded by the European Commission as ‘a milestone in our ongoing work for cleaner and more sustainable cars’, new regulations for car emission testing became mandatory across the EU on 1 September 2017. They are designed to more closely reflect fuel economy and emissions when actually driving and include an additional so-called ‘real-world driving emissions’ (RDE) test to detect regulated pollutant emissions. The RDE is to be carried out on the road using a portable emissions measurement system to record emissions.

The European Council says this ‘fundamental’ overhaul of the existing type of approval system was already in the EU’s work programme before the Volkswagen (VW) emissions scandal, in which VW exploited loopholes in the laboratory testing procedures, hit the headlines in 2015. The Council points out that Commission proposals to correct these shortcomings by measuring emissions in real driving conditions had already been published before the emissions scandal emerged in September 2015. But others have claimed that the European Commission had been warned by its own experts that a car maker was suspected of cheating emissions tests five years previously and kept quiet.

Whatever the truth, there can be no doubt that the discovery in 2015 of the use of so-called ‘defeat’ devices by some car manufacturers which resulted in public outcry and ongoing legal actions across the world will have helped to accelerate the adoption of these amendments.

Why do car emissions matter?

Emissions of air pollutants are the most significant environmental cause of premature death in the EU. They lead to respiratory diseases, major healthcare costs and lost working days. The most recent data indicates three air pollutants alone are responsible for 400,000 premature deaths per year in the EU including 70,000 directly linked to nitrogen dioxide (NO2).

Urban transport is one of the reasons why many urban areas are in breach of air pollution limits. It is a major issue for the UK where pollution causes an estimated 40,000 early deaths each year. Air pollution is worst overall in London, but many other places have unlawful levels of NO2 emitted by diesel vehicles, such as Leeds, Birmingham, Bournemouth and Northampton. Ipswich has higher levels of particulate matter than London. London breached its nominal annual air pollution limits five days into 2017 at Brixton Road in south London. Other known pollution blackspots include Putney High Street in west London, Oxford Street, Kings Road in Chelsea and the Strand. The UK has twice been found to be in breach of its EU obligations by the High Court.

The motor industry remains a significant player in both the UK and the EU. Apart from the activities currently dependent upon the car culture, 12.6 million people—or 5.7% of the EU employed population—work in the motor sector. The 3.3 million jobs in automotive manufacturing represent almost 11% of EU manufacturing employment. Motor vehicles account for almost €396bn in tax contributions in the EU15.

What are the regulated standards?

Emissions regulations date back to 1970, but the first EU-wide standard, known as ‘Euro 1’ was introduced in 1992. Catalytic converters became compulsory on new cars sold in the UK as Europe appreciated the need to reduce tailpipe emissions. This effectively standardised fuel injection on new cars. There have been a series of Euro emissions standards, leading to the current Euro 6, introduced in September 2014 for new type approvals and September 2015 for all vehicle sales and registrations. The regulations define acceptable limits for exhaust emissions of new light duty vehicles sold in EU and European Economic Area Member States. The aim of Euro emissions standards is to reduce the levels of harmful exhaust emissions, chiefly:

• nitrogen oxides (NOx)
• carbon monoxide (CO)
• hydrocarbons (HC)
• particulate matter (PM)
In respect of NOx emissions in particular, the EU has tightened the maximum NOx emissions limits for diesel passenger cars on several occasions, namely 500 milligrams per kilometre (mg/km) in January 2000, 250 mg/km in January 2005 (Euro 4), 180 mg/km in September 2009 and 80 mg/km in September 2014.

How are car emissions tested?

Before a car is allowed to be placed on the market, it needs to be ‘type approved’—the national authority needs to certify that the prototypes of the model meet all EU safety, environmental and conformity of production requirements before authorising the sale of the vehicle type in the EU.

Hitherto, only a laboratory test has been used to measure the air pollution emissions of a vehicle. That test is called the New European Drive Cycle (NEDC). However, for pollutants such as ultrafine particles and NOx, emissions of some vehicles measured once out on the road in reality substantially exceed the emissions measured on the currently applicable laboratory test cycle.

Is the system working?

These standards have certainly had a positive effect. The Society of Motor Manufacturers and Traders (SMMT) claims: ‘It would take 50 new cars today to produce the same amount of pollutant emissions as one vehicle built in the 1970s.’ The SMMT gives the following figures in support:

• CO: petrol down 63%, diesel down 82% since 1993
• HC: petrol down 50% since 2001
• NOx: down 84% since 2001
• PM: diesel down 96% since 1993

But the EU has pointed out that NOx emissions from road transport ‘have not been reduced as much as expected, since emissions in real-life driving conditions are often higher than those measured during the approval test (in particular for diesel vehicles)’. In December 2016 the UK government highlighted that road transport still accounted for 34% of UK NOx emissions in 2015. The rate of reduction in atmospheric NOx has slowed down due to the increased contribution from diesel vehicles.

The VW emission scandal has shown that some cars on the road today do not respect these values under real driving conditions, meaning more pollutants are released into the air. As VW proved, car makers can still bypass these regulations without doctoring a test model. This was because the NEDC used to test vehicles was not fit for purpose. Described by Auto Express ‘as riddled with loopholes allowing makers to “optimise” economy figures and quote emissions far below those that would be achieved in the real world,’ NEDC was designed in the 1970s and 1980s and due to evolutions in technology and driving conditions is quite simply outdated.

The EU has developed a new test, called the Worldwide Harmonised Light Vehicle Test Procedure (WLTP). While the NEDC test determined test values based on a theoretical driving profile, the WLTP cycle was developed using real-driving data, gathered from around the world. WLTP therefore better represents everyday driving profiles.
The WLTP driving cycle is divided into four parts with different average speeds—low, medium, high and extra high. Each part contains a variety of driving phases, stops, acceleration and braking phases. For a certain car type, each powertrain configuration is tested with WLTP for the car’s lightest (most economical) and heaviest (least economical) version.

The new RDE test measures the pollutants, such as NOx, emitted by cars while driven on the road. The RDE does not replace but is in addition to the WLTP laboratory test. RDE serves to confirm WLTP results in real life, ensuring that cars deliver low pollutant emissions, not only in the laboratory but also on the road.
Under the RDE, a car is driven on public roads and exposed to a wide range of different conditions. Specific equipment installed on the vehicle collects data to verify that legislative caps for pollutants such as NOx are not exceeded.

What is the RDE test?

In the RDE procedure, pollutant emissions—which include NOx and particulate emissions—are measured by portable emission measuring systems (PEMS) attached to the car while driving in real conditions on the road. This means the car will be driven outside and on a real road according to random variations of parameters such as acceleration, deceleration, ambient temperature, and payloads.

The Commission also plans to table a proposal in the coming months to further strengthen RDE legislation by adding the possibility of independent testing by third parties for checks of cars already in circulation (‘in-service conformity’ testing), introducing new and more representative methods for testing hybrid vehicles and adapting provisions for certain special vehicle types.

What is the conformity factor in the RDE test procedure?

Contrary to a pre-defined laboratory test cycle, the intrinsic characteristics of the PEMS measurement equipment in RDE tests leads to a higher variation and wider range of the quantitative emission results of different RDE trips. If the technical and statistical uncertainties of RDE measurements are not duly taken into account, it might happen that vehicles which are actually compliant could fail an individual RDE test or vehicles which are actually non-compliant could pass.

The concept of conformity factor helps overcome this problem. With a conformity factor, the focus is put on the vehicle’s average compliance with emission limits. For example, regulatory emission limits may be exceeded when driving up a steep hill, which then must be compensated by emissions below the regulatory emission limits under different conditions, such as driving moderately in the city, so that the average emissions, when weighing these conditions according to their statistical occurrence, are not above the limits.

Given the newness of RDE test measurements and the technical limits to improve the real world emission performance of currently-produced diesel cars in the short term, Member States agreed in October 2015 on a phasing-in period for reducing the divergence between the regulatory limit measured in laboratory conditions and the values of the RDE procedure.

What about CO2 emissions testing?

The Commission also has WLTP for measuring CO2 emissions and fuel consumption from cars and vans. The WLTP is a globally harmonised test procedure developed within the UN Economic Commission for Europe with the support of the European Commission.

Will the new system work?

While the WLTP provides a more realistic representation of conditions encountered on the road than the NEDC lab test, it will not cover all possible variations. Indeed the Commission admits that ‘atmospheric conditions will affect the results of this test’.

Furthermore each individual driver will have a different driving style—one driver might accelerate faster, take corners faster or brake more suddenly than another who might drive more conservatively. Accordingly, given that driving behaviour, traffic and weather conditions will continue to differ from one country to another, there will still be a difference between emissions measured in lab conditions and the real world. However, as there is no single real-world emission value, only values obtained by standardised laboratory tests allow us to directly compare the emissions and fuel consumption of different car models from different car manufacturers.

WLTP was developed with the aim of being used as a global test cycle across different world regions, so pollutant and CO2 emissions as well as fuel consumption values would be comparable worldwide.

However, while the WLTP has a common global ‘core’, the EU and other regions will apply the test in different ways depending on their road traffic laws and needs. Nonetheless, experts have broadly welcomed the change. Nick Molden, CEO at Emissions Analytics, says: ‘[T]he RDE test is what the industry has long been in need of. It is a substantial improvement over what we have today,’ he explains. ‘The current lab cycle is very gentle, which has led to real-world emissions being on average five times above the legal limit.’

What are the Commission’s next steps?

The Commission accepts that while ‘[the] new test procedures will make emissions measurements more realistic and accurate, and to a great extent reduce the risk of cheating with defeat devices’ a wider overhaul of the actual type approval system is needed. In January 2016 the Commission proposed a new Regulation to overhaul the current type approval system. According to the Commission:

‘The proposal aims to reinforce the independence and quality of technical services designated for the testing and inspection of the vehicle’s compliance with EU type approval requirements, introduce an effective market surveillance system to control the conformity of cars already in circulation, and introduce greater European oversight.’

This includes the possibility for the Commission to suspend, restrict or withdraw the designation of technical services that are underperforming and too lax in applying the rules. The Commission would also be able to carry out ex-post verification testing (through its Joint Research Centre) and if needed initiate recalls. Under the proposal, the Commission would be allowed to impose financial penalties to deter manufacturers and technical services from allowing non-compliant vehicles onto the market.

The Commission’s proposal maintains the current ban on defeat devices, which national authorities have a standing obligation to police and enforce, but goes a step further. Under the draft Regulation, the manufacturer will have to provide access to the car’s software protocols. This measure complements the RDE package, which will make it very difficult to circumvent emission requirements and includes an obligation for manufacturers to disclose their emissions reduction strategy, as is the case in the USA. The Commission is seeking to put pressure on the European Parliament and Council to now swiftly conclude their negotiations on this proposal.

Filed Under: Environment

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