On Thursday, together with my Environment Committee colleagues, I questioned Matthew Pencharz – Mayor’s adviser on energy and environment, Oliver Lord – Air Quality Manager, GLA and Sam Longman – Policy Manager (Environment), Transport for London on the Volkswagen emissions scandal that has recently broken.
Though there has been a recent media storm about the admissions from Volkswagen, it has been known for some years that emissions of modern vehicles on the road are higher than the levels required under Euro emissions standards.
A well-known issue is that the driving cycle used to test compliance with the standards does not reflect real-world driving, and especially not low-speed stop-start urban driving. In urban driving, diesel engines run less efficiently and work harder than in steady driving on the open road, burning more fuel. Also, their pollution-reduction measures work less well, since they are set up to perform best in the high-speed distance driving typical of the test.
During our investigation into the impact of diesel engines on London, the Environment Committee heard that there will always be differences between test conditions and real driving, because test conditions must be consistent and real-world driving is very varied.
At the Committee meeting we discussed how special tactics may prevent tests reflecting on-the-road performance even for the type of driving the test is intended to simulate.
Manufacturers reportedly submit cars for testing that have parts removed to reduce weight (such as the sound system and even wing mirrors), special lubricants in the engine, special tyres filled with special gas, and gaps around doors and panels taped over to reduce drag.
Overall, the average car in Europe delivers 38% worse economy on the road than it achieves under laboratory conditions. Many of these adjustments are made because the tests are commissioned by the manufacturers, and the testing labs compete for business by offering any favourable circumstances, or permitting any special car setup, not ruled out by the test specifications.
Recently, Volkswagen has admitted using special engine software to put cars into a low-emission mode for US tests, meaning that emissions on the road could be up to 40 times higher than certified under US standards. The same models are used in Europe, including 1.2 million vehicles sold in the UK under brands including VW, Audi, Seat and Skoda. The vehicles look set to be recalled.
These issues have been reflected in the Committee’s diesel emissions report: see in particular paragraphs 3.8 and 3.13-3.15, including Recommendations 4 and 5. Key points included that the Mayor should lobby the EU for effective testing, and report progress to this committee by the end of 2015, and that TfL should monitor real emissions on London’s roads and explore with the EU the possibility of removing ULEZ exemption from vehicles that do not meet emissions standards in real urban driving.