‘It appears the diesel car industry is reluctant to fix the emissions problem once and for all.’

by Amit Panday 07 Sep 2017


Anup Bandivadekar, who was part of the ICCT team which commissioned and designed the study that ultimately led to the discovery of the VW Dieselgate scandal, spoke to Autocar Professional's Amit Panday on the recent findings of the ICCT-ICAT study titled ‘'Development Test Report on Laboratory and On-Road Emissions Testing of In-Use Passenger Vehicles in India’. The detailed research report highlights that most light-duty diesel and petrol vehicles in India emit much more in the real driving conditions than what they claim on paper. Excerpts:

What are the findings of the recent ICAT-ICCT tests performed on the in-use Mahindra XUV500, Hyundai i20 diesel and i20 petrol cars?
Chassis testing (laboratory) shows the following:
- Petrol car emissions are below standard values.
- Small diesel car emissions are higher than small gasoline car as expected, and emissions increased from cold start to hot start.
- Diesel SUV just barely met the relaxed standard for vehicles of higher weight under cold start, but emissions increased under hot start
- Particulate number (PN) emissions from diesel vehicles are 6e13 to 1e14 range. Of course, these vehicles do not have a DPF. Diesel vehicles with a DPF could be expected to have PN emissions nearly 1000 times less than this.

PEMS testing (on-road):
- Gasoline NOx emissions were 0.5-0.7 times the standard
- Diesel car NOx real driving emissions are 3x - 4x the standard Thus, NOx emissions from i20 diesel is 9 to12 times i20 petrol NOx as the diesel car NOx standard itself is three times that of gasoline
- Note that the NOx standard for diesel SUV is 5 times that of gasoline standard. Diesel SUV real world NOx emissions are 4-6 times the already weak NOx standard. Thus, NOx emissions from XUV diesel SUV are 25 to 65 times i20 petrol NOx emissions

What is being done to improve the existing testing procedures and real driving emission (RDE) tests in India compared to other countries globally?
In the EU, the World Light-Duty Testing Procedure (WLTP) is being adopted from this year. Japan, China and South Korea have all agreed to implement the WLTP over the next three years as well. India, by contrast, has not yet made any decision on adoption of WLTP. The WLTP is a major improvement over the current NEDC/MIDC, and adopting the WLTP would lead to manufacturers having to design more robust emission controls, and more realistic fuel efficiency values.

On the Real Driving Emissions (RDE) front, EU has already adopted the regulation, but its implementation is being phased over several years. The fourth package of RDE, consisting of requirements to rest in-use vehicles is currently being finalised. China has lardy adopted all of the RDE requirements, but has relaxed the boundary conditions imposed in EU. As a result, meeting in-use RDE emissions will be more challenging there. 

India has indicated its willingness to adopt PEMS-based RDE, but the details have not been finalised. Several manufacturers have indicated that they would prefer additional laboratory testing over PEMS based RDE testing.

What should ideally be done with the existing fleet of vehicles that emit pollutants beyond the regulatory limits in India?
The answer differs for cars and commercial vehicles. In case of commercial vehicles, all BS II and earlier vehicles should be provided a fiscal incentive to scrap the vehicles. After 2020, the incentive should be made available to scrap BS III commercial vehicles as well, with a 2027 deadline after which all pre-BS IV commercial vehicles should either be scrapped or mandatory retrofitted with a diesel particulate filter. After 2030, even BS IV vehicles should be required DPF retrofits if they are to ply on the road.

In case of cars, scrappage or retrofit are not necessarily cost-effective solutions unless those costs are borne by the manufacturers of the diesel vehicles. Several cities across the world are coming up with different types of solutions to discourage vehicles that are polluting beyond regulatory limits.

Some cities have imposed a pollution charge, some others are restricting registration of older diesel cars, while others are considering outright bans on diesel cars, unless the cars are retrofitted with better emission controls. Thus, the solutions are not unlike discussed in India — like the NGT order on removal of diesel cars >10 years from Delhi, or the Supreme Court decision to impose a pollution charge on diesel cars. Our assessment is that the currently levied 1% pollution charge on diesel vehicles >2L engine size is quite inadequate to compensate for the public health impacts caused by these vehicles. 

In the absence of any statutory requirement on the real world emissions, will the existing vehicles continue to pollute until 2020? Is this happening only in India or in other countries too?
Unfortunately, once vehicles that are emitting high emissions are on the road, it is much harder to do something about the problem. The US implements a rigorous in-use compliance program that hold manufacturers responsible for keeping emissions low throughout the useful vehicle life. Most other places, including India, lack such a rigorous in-use compliance program. 

Note that the RDE tests in India — currently not finalised — are not supposed to take effect until 2023. As a result, the risk is that real-world NOx emissions of diesel cars and SUVS continues to be high at least until 2023. If the form of adopted RDE requirements is weak, in-use emissions of diesel cars may continue to be several times higher than their gasoline counterparts for quite some time to come.

Do you think that the light-duty diesel engines have no option but to take the EGR + SCR route in order to comply with the BS VI emission norms in India by 2020? Some say that lean NOx trap (LNT) might also be used instead of the SCR tech. What are the pros and cons of using the LNT system in the vehicle? Is there a possibility that the small car OEMs in India will opt for LNT units under the BS VI regime?
You are right that the economics of using LNTs is better for smaller diesel engines as compared with the SCR. However, we have observed that LNT-only vehicles have so far not functioned well either under WLTP or under on-road PEMS tests. This makes the position of diesel engines in small cars particularly tenuous. Real-world emissions from these vehicles will have to tracked very carefully in India.

Ultimately, individual OEMs and their suppliers will determine what technology pathway to choose, but it seems that EGR+SCR would be a preferred solution for those who are trying to minimise real-world emissions. This does not mean that there is no future for LNTs. We have seen BMW successfully deploy LNT+SCR combination to keep low real-world emissions of NOx. 

After nearly two years to the VW Dieselgate scandal, what are the key takeaways on the role of OEMs and their suppliers, strategies to keep costs under check, future of diesel engine and other critical areas?
Two years after Dieselgate erupted, it is not clear yet if the lessons of the scandal have been internalised. Regulators have made some efforts to improve regulations and to pay more attention to compliance and enforcement, but our soon-to-be-released review of such practices around the world suggests that there is much room for improvement.

Some manufacturers and their suppliers have also taken positive steps to design more robust emission controls including on-board diagnostics, but by and large manufacturers appear reluctant to commit to mandatory rigorous on-road emissions testing around the world, and content to pass the laboratory tests irrespective of the real-world emissions impact of their vehicles. The unfortunate outcome of this is that the patience of local authorities in charge of local air quality is wearing thin, and they longer seem to be in the mood to continue to give diesel vehicles a free pass. 

Competition to diesel cars continues to mount. For example, Delphi just announced a gasoline 48v mild-hybrid plus cylinder deactivation solution that they claim is cost competitive with diesel in terms of costs and efficiency, without any of the headaches of diesel after treatment. Mazda has announced that they are taking a massive leap forward by deploying homogenous charge compression ignition (HCCI) from 2019. Mazda states that they expect this engine to equal or exceed the fuel efficiency of a comparable diesel engine. 

So, the message for diesel car manufacturers is clear — first, leave no stone unturned to ensure low emission performance across a wide range of operating conditions throughout the useful life of their vehicles, or be prepared for increasingly restrictive environment in which these vehicles can be operated, and rapidly declining resale values.  Second, be prepared for an increasingly fierce competition from improved gasoline, hybrids, and electric vehicles that are putting into question relevance of diesel vehicles in a carbon-constrained world. In short, any further investments in diesel passenger cars should be scrutinized carefully. 

Do you think that diesel car sales have peaked in India and the world?
On one hand, it would be premature to count of technological innovation that solves the emissions problem with diesel cars and improves their competitiveness. On the other hand, it appears that the diesel car industry is reluctant to fix the emissions problem once and for all.

Personally, I think that the outlook for diesel cars is not positive going forward. Market share of diesel cars is on a downward trajectory in EU and India in recent months. If the current trends — increased focus on in-use diesel emissions, reduced tax gap on gasoline and diesel fuel, restrictions on use of older and polluting diesel cars in major cities — then diesel cars may find it hard to make a comeback. 

Do you think hybrid vehicles will become mainstream before the electric vehicle market takes off in the future in India?
It is difficult to make projections about which technology may emerge as the ‘winner’. There is tremendous technological innovation taking place in the automotive industry, and the most plausible outcome at this stage appears that there will be at least some room for all powertrains in the light-duty market (cars, SUVs and small commercial vehicles).

The prudent course of action is to continuously tighten the emission and efficiency standards, and provide ample lead time to the industry to figure out what solutions will work best in which context.

What are your thoughts on NITI Aayog’s recent mobility roadmap for India?
NITI Aayog’s report on mobility roadmap presents a large menu of plausible technology and policy interventions. What is needed at this stage is to narrow down this broad menu to a set of actionable near-term projects and test the feasibility of various suggested pathways.

Also read: Autocar Professional's September 1, 2017 issue reveals how some Indian passenger vehicles’ real-world emissions exceed their emission levels claimed on paper. 

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