Why clean diesel is a myth in India?

January 07, 2011

Hell broke lose when the environment minister Jairam Ramesh called SUVs criminal for guzzling cheap subsidized diesel. He is right -- The real beneficiaries of the diesel subsidy are the owners of "BMWs, Benz and Hondas'', and not the farmers. He pitched for reforms in diesel prices; penalty on those who use subsidized diesel for luxury use in SUVs.

Indian auto industry erupted to claim that their diesel cars are clean and efficient. Most unexpected was the reaction of the German envoy in India who took exception to the Minister’s statement and defended its big car brands – Mercedes Benz and BMW. He claimed that “German automotive technology is far advanced in reducing both fuel consumption and fuel emissions." It is ironical that the German government should defend its brands when it knows that the subsidised Indian diesel does not meet the global clean benchmark. Germany itself has faced a massive civil society campaign against dirty diesel. In the face of serious public health threat Germany was compelled to introduce 10 ppm diesel fuel and mandate particulate filter in cars. Germans civil society had asked – should there be particulate filters on the car exhaust or on their nose?

How can Germany defend big cars in a predominantly small car market of India? Despite the engine improvements Germany itself has witnessed continues increase in weight and power of new engines over the decade. The same German brands spew CO2 in the range of 151g/km to 167 g/km. Many poplar small cars in India are equal or less than 140 g/km. If German ambition and Indian aspiration shifts the Indian market towards these bigger cars India will lose its advantage.

Added to this is the public health cost of not so clean diesel. Very few people in India understand why even after meeting Euro III and Euro IV emissions standards, serious concerns persist regarding the toxic diesel emissions.

The Right To Clean Air campaign of the Centre for Science and Environment presents this fact sheet. Is clean diesel a myth or part of the solution?



Why is the German Envoy wrong in defending the big and luxury German diesel car brands in India?


How can Germany ignore the high level of diesel related pollution in Indian cities – particulates and nitrogen oxides?


How the threat of gas guzzlers looming large in India?


How can our government be asked to shoulder the burden of subsidy to the rich car owners?


How can auto industry claim that the current Bharat Stage III and IV diesel car fleet meet clean benchmark?


How can the car industry ignore the evidence of higher toxicity of the diesel emissions?


Did you know there are doubts about the climate benefits of conventional diesel?


Q.8) What should the government do?

Why is the German Envoy wrong in defending the big and luxury German diesel car brands in India?

Ans.1) Europe is the favourite example of the Indian auto industry to defend its business model based on bigger cars and diesel. It claims diesel cars are efficient and Europe is encouraging diesel cars. But look what has happened in Europe. The average power of the fleet has increased gradually by 30 per cent since 1990.The European Union had started by setting the most ambitious target for CO2 emissions reduction from vehicles. Though this has helped to lower CO2 emissions from new cars in the EU-15 countries by 12.4 per cent from 1995 through 2004, the car makers could not meet the original 2008/9 CO2 emission target of 140 g/km. The target represented about a 25 percent reduction from the 1995 average fleet-wide CO2 level of 187 g/km. It was originally agreed that the fleet-wide sales weighted average target of CO2 emissions will be reduced to 140 gm/km by 2008 and 120 gm/km by 2012. During 2005-06 it became clear that the industry would not be able to meet the target of 140 g/km in 2008. In fact, the current fleet wide average attained in the EU15 countries is still above 160 g CO2/km.

During 2008, carmakers lobbied aggressively to extend the deadline. They will now meet the 2008 target of 140 gm/km in 2012. Furthermore, the EU postponed the next target year from 2012 until 2015 and diluted the target from 120 gm/km to 130gm/km. During all these years time new cars sold in the EU have become significantly bigger and more powerful.

Dieselisation has also complicated air pollution control in Germany and Europe. Indian auto industry often cites increase in diesel cars in Europe to support their diesel based business model. But it is evident that due to dieselization some European cities have been at risk or are already violating air quality targets for NOx and PM10. In fact, Europe has also revised their ambient air quality guidelines. Accordingly, the PM10 standard (24 hourly average standard of 50 microgrammes per cubic metre) must not exceed on more than 35 days in a calendar year. Many European cities like Munich, Stuttgart, Dusseldorf, Berlin, have exceeded the air quality standards and the civil society has dragged the city authorities to Court.

Concern over diesel emissions has also led countries like Germany to launch clean diesel campaign and mandate fitment of particulate traps along with diesel fuel with sulphur content as low as 10 ppm. Clearly, it makes no sense for European car makers also to expand diesel car fleet when India does not have clean diesel. Also Europe has not yet been able to solve the problem of NOx emissions. Due to the primacy attached to fuel economy or CO2 emissions diesel cars are now getting caught in the trade-off between NOx and fuel efficiency. While the future PM emissions norms under Euro V and Euro VI will close gap with the more stringent US emission standards, the NOx norms will continue to remain comparatively lax. This is because meeting equally stringent NOx and PM levels and tight fuel efficiency target present a difficult engineering challenge in diesel engines.

Therefore it is important that India recognises the inherent flaws of the European approaches and not repeat the mistake. We cannot afford to allow the problem to grow and then deal with the pollution aftermath. It is important to be precautionary and stem the tide at the early stages of motorisation.

Why Germany, even after meeting Euro IV standards, campaigned against diesel?

On November 25, 2002, a coalition of German environmental groups issued a press release to declare the initiative “No diesel without filter”, which stated that the automobile industry would only sell diesel cars with soot filters (DPF) from the summer of 2003. The WHO, the Umweltbundesamt (federal environmental agency, the UBA) and many other organisations were partners to this initiative.

This has raised a critical question: where does one want to have the filter — in the exhaust or in the pollution mask? Industry’s position, as usual, was that filters are not needed, are technically not possible, and, are too costly. On February 27, 2003, a press release from the industry stated, “German automobile industry will not use soot filters because of cost reasons.”

This triggered off protests by Greenpeace “Diagnose allergien” in front of the DaimlerChrysler office, where people were put on hospital desks as they were diagnosed for allergy or cancer. This was followed by a huge hoarding on the wall of the new Volkswagen building depicting a child wearing a mask and saying, “Diesel macht krebs” (diesel causes cancer). In Berlin, there was a demonstration in front of a park saying, “ban diesel…our children are in danger because diesel smoke endangers your health.”

The German government decided to take action against diesel vehicles as diesel particulates are known to cause heart and lung diseases. A study conducted by the Institute of Epidemiology in Neuherberg, Germany showed that the use of diesel particulate filters (DPFs) can prevent 14,400 premature deaths per year. The results were re-checked to see if the danger was overestimated and even in alternative scenarios, the number of deaths that could be avoided ranged from 9,600-19,200 per annum. The country took the decision, therefore, to promote DPFs even though particulate levels in Germany are much lower than that in India.

Source: Excerpts of presentation by Axel Friedrich at CSE conference: The leapfrog factor, New Delhi, April 2004


How can Germany ignore the high level of diesel related pollution in Indian cities – particulates and nitrogen oxides?

Ans.2) Diesel-related emissions are already very high in the air of Indian cities. The air quality data from the Central Pollution Control Board shows that the average levels of tiny particulates, smaller than 2.5-micron size (PM2.5), that go deep inside lungs, have hit a dizzying heights in cities like Delhi. The WHO has said that there is no safe level for PM. Studies in the US show that even at very low concentrations and with an increase of only 10 microgram per cubic metre, PM2.5 is associated with significant increases in health risks like asthma, lung diseases, chronic bronchitis and heart damage.Long-term exposure can cause lung cancer. What’s worse, in Delhi, levels of nitrogen dioxides (NO2) are also spiraling adding to the problem of ozone. Both PM and NOx dominate diesel exhaust emissions.


How the threat of gas guzzlers looming large in India?

Ans.3)The available estimates of the market share of different car segments are an eye opener. Only the multi purpose vehicle segment, or the so called SUVs, is already 8 per cent of the sales. If we combine this with the bigger segments cars (A4 onwards) then the market share of these cars is nearly 30 per cent. Even though the smaller car segment (A2) is still substantial (58 per cent) a steady increase in the bigger car segments and SUVs can substantially erode the fuel economy advantage of small car fleet that India has enjoyed so far. The on-road surveys carried out by RITES also show that 30 per cent of the cars on Delhi’s roads are already mid-size and large cars. With further increase in big cars the total fleet’s fuel economy will worsen nationally.

It is evident that the fleet wide fuel economy of Indian fleet is already stagnating over the last three years and this year after the voluntary declaration of fuel economy data there has been one percent improvement. But it is clean from the fuel consumption profile of each car segment that any shift toward bigger cars can worsen the average fleet fuel economy (See the table below). The smallest car segment – the Nano – consumes on an average 5.90 litres of fuel per 100 km and the A2 segment as represented by such models as the Alto and Hyundai i10 about 5.40 litres per 100 km. But the A5 cars (like the Mercedes E Class E-250) and A6 (Audi A8) consume 8.51 litres per 100 km and 9.76 litres per 100 km respectively. The range in the biggest segment (B1 B2 and MPVs) is from 7.30 to 8.19 litres per 100 km. This clearly brings out the serious implication for the energy demand in the car segment if we begin to see more shifts from A2 to the bigger classes.

It is evident from global studies such as that of the International Council on Clean transportation that a 10 per cent increase in large vehicle sales can roughly result in 2 to 3.5 per cent deterioration in fleet fuel economy. Even at 2 per cent deterioration, roughly, an additional 17,500 barrels of oil will be consumed annually by those 10 per cent large vehicle sales. Why the Indian government should let the country and the climate to bear this unacceptable cost on account of luxury consumption? Greenhouse gas emissions are highest from the personal car fleet in the transport sector of Delhi, for instance.

Table: The current market shares and fuel consumption of different market segments 2009-10
Market Segment Representative Vehicle Average Fuel Consumption of the segment (l/100km) Market share (2009-2010)
A1 Tata Nano 5.90 5.9%
A2 Maruti Alto/Hyundai i10 etc 5.40 58.4%
A3 Honda City etc 5.87 14.2%
A4 Skoda Octavia/Fiat Linea etc 6.46 2.5%
A5 Mercedes E Class E-250 8.51 0.6%
A6 Audi A8 etc 9.76 0.1%
B1a Chevrolet Tavera etc 8.19 5.6%>
B1b Toyota Innova etc 7.46 4.2%


Tata Sumo Victa etc 7.62 0.5%
MPV Mahindra Scorpio etc 7.30 8.0%
TOTAL   5.95 >100.0%

How can our government be asked to shoulder the burden of subsidy to the rich car owners?

Ans.4)The Union government earns much less from excise on a litre of diesel used by cars, as opposed to petrol; revenue losses per litre of diesel will be compounded with increase in diesel car sales. But diesel car owners recover their premium within a few years, given lower diesel prices. This perverse subsidy to the rich comes at an enormous cost to public health. In countries like Brazil, diesel cars are actively discouraged because of the policy to keep taxes lower on diesel. In Denmark, diesel cars are taxed higher to offset the lower prices of diesel fuel. In China, taxes do not differentiate between petrol and diesel fuels.

Cheap diesel is also leading to more oil guzzling in the rebound: Studies in Europe have shown how use of cheaper diesel used in bigger vehicles and SUVs that are also used for long distance driving undermines the efficiency gains of improved vehicle technology. The actual fuel consumption goes up. Other governments are increasing taxes on bigger cars, especially SUVs – most exemplary is the case of China – to minimise the energy and pollution impacts of these vehicles.

Consumers actually end up spending more on fuel during the life time of large cars. SUVs particularly are captive users of diesel. This defeats the government’s objective of improving vehicle fuel economy to protect India’s energy security and meet its climate goals. Dirty air increases the medical bills of the consumer.


How can auto industry claim that the current Bharat Stage III and IV diesel car fleet meet clean benchmark?

Ans.5)Bharat Stage III and IV emissions standards legally allow diesel cars to emit several times more NOx and PM than petrol cars. It is a myth that the diesel car technology that is available currently in India is clean and meets the public health objective. Auto industry claims that they are adopting common rail injection systems for diesel cars and therefore they are clean. But our emissions standards are not fuel neutral as they differentiate between petrol and diesel vehicles. The difference is evident in the emissions factors developed by the Automotive Research Association of India for Bharat Stage III diesel cars that are sold across the country. These diesel cars emit 7.5 times more toxic particulate matter than comparable petrol cars. This means, one diesel car is equal to adding 7.5 petrol cars to the car fleet in terms of PM emissions and three petrol cars in terms of NOx emissions. Total air toxics from a diesel car that are very harmful and carcinogenic are seven times higher than that from petrol cars.

Graph: Diesels have unfair emission advantage
Diesels are legally allowed to emit nearly three times more NOx in Bharat Stage III and BS IV (Euro 3 and 4 equivalent norms)

(A) NOx norms for cars


(B) PM norms for cars

Note: Mass PM emissions from petrol cars is considered negligible hence it is not regulated.
Source: Anon 2004, Notification No G.S.R. 686 (E), dated 20th October 2004 – Bharat Stage III emission norms, Ministry of Shipping, Road Transport and Highways
Anon 2002, Report of the expert committee on Auto Fuel Policy, Government of India, New Delhi, August

How can the car industry ignore the evidence of higher toxicity of the diesel emissions?

Ans.6) Diesel and petrol cars meeting the same level of emission norms have different toxicity levels that determine the cancer causing potential. Data from Europe shows that the diesel cars’ toxicity becomes comparable with petrol only when they are fuelled with near zero sulphur fuel and are fitted with particulate traps. The International Agency for Research of Cancer (IARC), WHO, United States Environmental Protection Agency, etc have all classified diesel emissions as carcinogenic. The European Commission has calculated the difference in lifetime pollution costs of Euro IV-compliant diesel car and petrol car -- and it shows a major difference. The total pollution cost of a Euro IV diesel car is 1,195 Euros vis a vis 846 Euros for a petrol car. This nullifies the marginal greenhouse gas reduction benefits of diesel car and costs higher to the society.

Graph: Toxic profile of diesel and petrol cars meeting Euro norms
A comparison of toxicity of emissions from diesel and petrol passenger cars meeting different norms in urban traffic

Source: Michael Walsh 2003, The global impacts of heavy-duty diesel vehicle emissions, USA, mimeo

Did you know there are doubts about the climate benefits of conventional diesel?

Ans.7)Even low carbon emissions advantages of diesel cars are shrouded in doubt. Diesel cars are popular for their greater fuel efficiency and lower heat-trapping carbon dioxide emissions. ARAI data shows Euro III Indian diesel cars emit 1.2 times less carbon dioxide compared to their petrol counterparts. But even this benefit is at risk of being negated as diesel fuel has more carbon content than petrol. If more diesel fuel is burnt, as is likely given its cheaper prices and rising number of cars and SUVs, the heat-trapping carbon emissions will increase.

The warming potential of diesel black carbon further erodes the climate benefits of diesel. In fact a study carried out by the scientists of British Columbia on the Delhi CNG programme has found that in comparison with the warming potential of black carbon emissions from the older diesel bus fleet that the CNG fleet has replaced, the CNG bus fleet has been less warming despite the methane emissions from the CNG vehicles. When black carbon emissions from diesel bus fleet is taken into account the CNG switch becomes carbon neutral as it leads to upto 30 percent reduction in CO2 (e).


What should the government do?

Ans.8) CSE proposes the following action plan:
  • Discourage big cars and SUVs by linking taxation to the actual fuel consumption of the vehicles. More fuel a vehicle consumes the more tax should it pay. It is more scientific and effective to link the tax policy to actual fuel consumption. The current tax policy differentiates between small and large vehicles on the basis of engine displacement, and the taxes on larger engine size vehicles are almost double that of the small vehicles. But this should be more effectively linked with graded fuel consumption.

  • Remove price incentive for diesel cars. Either equalise fuel taxes and prices or impose effectively high additional taxes on diesel cars to neutralize the current fuel price advantage that the cars enjoy. Kirit Parikh Committee has already recommended additional taxes on diesel cars to neutralize the benefit of fuel price difference. This should be immediately designed more effectively and implemented.

  • Introduce ‘clean’ diesel technology and fuel on a nation-wide basis: India needs to set the timeline for the uniform introduction of clean diesel with sulphur content less than 10 ppm and mandate use of advanced particulate traps to near eliminate toxic particulates. Otherwise, we need to get off the diesel route.

  • Need post 2010-emissions standards roadmap to reduce the pollution impact of motorization: At this moment there is no roadmap for uniform introduction of Euro IV and Euro V emissions standards across the country. The stepped approach of introducing tighter standards only in 13 cities benefits less than the quarter of urban population whereas the CPCB data shows that pollution levels are high across many small and big cities. It is time to give early deadline to the automobile industry to prepare for the next target of emissions standards and close the time lag with Europe. If needed design fiscal policies for the refineries to meet the cost of fuel quality improvement.

  • Fuel economy standards must not worsen the trade-off between fuel efficiency of diesel cars and their toxic emissions. Fuel economy standards currently in the making must have built-in safeguards against dieselization of car fleet. Fuel efficiency regulations will always give advantage to diesel cars especially if the industry pushes for average fleet-wide improvement targets. Industry will end up expanding the diesel car fleet to improve the fleet average. But in this number game the toxic impact of diesel fume will increase manifold and endanger public health.



Down to Earth

July 01, 2017

State of endosulfan

September 20, 2017

Cess on diesel car

September 20, 2017

Count the soot

September 20, 2017

Fatal attraction

September 20, 2017

Licence to kill

September 20, 2017

No diesel without filter


March 30, 1999

Engines of the Devil

Fact Sheets