Diesel Engine Vs Bharat Stage VI

Diesel Engine Vs Bharat Stage VI
Diesel Engine Vs BS VI
On April 25, Maruti Suzuki, India’s top carmaker, announced that it would phase out production of diesel models from April 1, 2020, when stricter Bharat Stage VI emission standards come into force. What does this mean for the auto industry?
Explaining its rationale, the leading passenger vehicle manufacturer said the enhanced emission standards would make diesel engines costlier by up to Rs 1.5 lakh, and the acquisition cost of diesel vehicles for consumers would be markedly higher than petrol equivalents. Given the market dynamics, it would not make business sense for the company to invest in developing new diesel engines to meet the BS VI norms. Compressed Natural Gas could be a replacement for both fuels, according to Maruti.
On the consumer side, diesel vehicles are not particularly attractive. The traditional advantage of lower operating costs due to a wide gap between expensive petrol and lower cost diesel has narrowed significantly. The price of diesel in a city like Chennai was Rs 70.48 per litre compared to Rs 75.92 per litre for petrol. Environmentally, diesel is a heavy polluter and is losing ground in leading passenger vehicle markets such as the European Union. The rigging of emissions data by Volkswagen to show lower levels of nitrogen oxides accelerated the move away from diesel. Even in Germany, which is a leading maker of diesel cars, cities want to ban them.
Ambient air quality has deteriorated so badly that 15 Indian cities led by Gurugram are among the 20 most polluted cities globally as per the IQAir AirVisual ‘World Air Quality Report’ for 2018, based on fine particulate matter (PM2.5) that penetrates the lungs and bloodstream. Transport emissions, particularly from diesel, are a major contributor.
The Auto Fuel Vision and Policy 2025 published by the erstwhile Planning Commission, which laid out the road map for a transition to less polluting fuels, pointed out that sulphur in diesel is a contributor to particulate matter both in the vehicular exhaust and in the atmosphere. Sulphur is found in petrol too, but for comparison, it was 2,000 parts per million (ppm) in petrol before introduction of standards in 2000, but in diesel it was 10,000 parts per million (ppm) in 1996. Sulphur content was reduced with each phase of upgradation of emission standards to touch 50 ppm under BS IV. In BS VI, which is already dispensed in Delhi, it is 10 ppm.
Sulphur plays a key role since higher concentrations have an impact on technologies for control of other pollutants in the emissions, such as carbon monoxide, particulates, oxides of nitrogen and hydrocarbons.
The importance of cleaner diesel was studied in Karnataka, and data show that adoption of Bharat IV diesel in 2015 had an impact on the sulphur dioxide (SO2) concentrations. The sulphur content of diesel changed from 350 ppm to 50 ppm. There was a 25% drop in nitrogen dioxide (NO2) concentrations too, which could also be linked to change in the fuel quality. But such gains were neutralised by traffic growth. The rise in larger PM10 concentrations by 50%, was linked to growing numbers of vehicles and dust resuspension, besides construction activity.
Air pollution is a leading contributor to non-communicable diseases and accounts for a large number of premature deaths. The World Health Organisation describes diesel exhaust as an occupational cancer-causing agent. In India, the Global Burden of Disease Study 2017 attributed 8% of the disease burden, and 11% of premature deaths in people below 70 years of age to air pollution.
Even with a reduction in the sulphur content in BS VI fuels, the health effects of lower emissions would be lost due to a growing number of vehicles. The best scenario to reduce PM2.5 exposure in India is, therefore, not just shifting to BS VI fuels but bringing about a reduction in use of private vehicles through augmented public transport and promoting alternative fuels including the use of electric vehicles.