Bharat Stage VI-grade fuel has already been introduced in Delhi from April 1, 2018. Kolkata has not yet tested the fuel and is scheduled to roll it out by March 2020. While the contribution of cars and bikes to the overall pollution remains a matter of debate, the introduction of higher grade fuel is undoubtedly a step in the right direction. Let’s study the matter in more detail. Bharat Stage Emission Standards (BSES) India’s vehicle emission standards (BSES) are modelled on the Euro emission standards that define limits for harmful exhaust emissions. The emission standards primarily focus on the reduction of Nitrogen Oxides (NOx), Carbon Monoxide (CO), Hydrocarbons (HC) and particulate matter (PM) emissions. Long-term exposure to air pollution can lead to respiratory and cardiovascular diseases, which was estimated to be the cause for 6.2 lakh early deaths in 2010. The health cost of air pollution in India has been assessed at 3% of its GDP. While the fuel norms help in bringing down pollution levels, it invariably results in a marginal increase of vehicle cost due to the improved technology and higher fuel prices. However, this increase in private cost is offset by savings in health costs for the public at large, as there is a lesser amount of disease caused by particulate matter and pollution in the air. The BSES standards are instituted by the Government of India to regulate the output of air pollutants from internal combustion engines and spark-ignition engines equipment, including motor vehicles. The standards and timeline for implementation are set by the Central Pollution Control Board under the Ministry of Environment, Forest and Climate Change. BSES was first introduced in 2000. Progressively stringent norms have been rolled out since then. All new vehicles manufactured after the implementation of the norms have to be compliant with the regulations. For instance, the phasing out of 2-stroke engines for two wheelers, the cessation of the production of Maruti 800 and the introduction of electronic controls have all been due to regulations related to vehicular emissions. Since October 2010, Bharat Stage (BS) III norms have been enforced across the country. However, in 2016, the Indian government announced that the country would skip the BS-V norms altogether which was scheduled to be launched in 2019 and instead adopt BS-VI norms by 2020. The decision caused some consternation among the automobile companies as they had planned the development according to the roadmap for 2020. Delhi Case Study As a case study, the Delhi government has in the past struggled to come up with a solution and hence, the odd-even rule was introduced as an idea despite it not being an effective tool to combat pollution. The reason is simple. Limiting the number of private vehicles on the road may halve the emissions they emit, but it is ineffective since private four-wheelers contribute to only 10% of the total vehicular pollution. Bringing that 10% down to 5% isn't going to make a really big difference to the poor air quality of Delhi. The next thing we know, the National Green Tribunal and the government were at loggerheads arguing about who should be included in the rule and who shouldn't. The government meanwhile shifted its plans and the Ministry of Petroleum and Natural Gas announced that they would fast-track the availability of BS-VI fuel in Delhi National Capital Region, bringing the new-gen fuel by April 1, 2018, instead of the pan-India rollout target of 2020. BS-VI Fuel The move from BS-IV to BS-VI will primarily require fuel to have significantly lower sulphur content. Presently, the sulphur content in BS-IV petrol and diesel is 50 parts per million (ppm). BS VI-grade fuels, however, are supposed to have a sulphur content of 10 ppm. While it is unlikely that BS-IV fuel will be altogether done away with, the major question that arises is whether there is any advantage of running your existing BS-III or BS-IV compliant car on BS-VI fuel when it becomes available. The answer is largely yes. In simple terms, the lower the sulphur content in the fuel, the cleaner it burns. Petrol with lower sulphur emits less NOx, CO and HC, while the advantage of low sulphur diesel is significantly lower particulate matter (PM) emissions. Estimates suggest that a BS-IV compliant car running on BS-VI diesel could emit 50 percent less PM. On the flip side, the process to reduce sulphur in diesel can negatively impact the energy content of the fuel, and correspondingly bring down the fuel efficiency by a small margin. There are also concerns over the lower lubricity and readiness to burn of ultra low sulphur diesel (ULSD). Then again, ULSDs come with additives that address these issues. But more than anything else, price could be the biggest detriment to the early adoption of BS-VI fuel. Fuel suppliers are investing thousands of crores to upgrade their refineries and are sure to pass on the outlay to consumers in the form of higher price. Effect of BS-VI fuel in BS-IV vehicle Now the question that arises: Is BS-VI fuel compatible with the existing old vehicles? Yes, overall there is no need to panic. In fact, there are more advantages of putting the new BS-VI fuel even on the current running BS-III and BS-IV compliant cars. The lower the sulphur content in the fuel, the cleaner it burns. This will result in lower emissions of NOx, CO and Hydrocarbons on the petrol-powered vehicles and on diesel engines, there will be a significant reduction in the lower particulate matter. Reports by ARAI suggest, that a BS-IV compliant car running on BS-VI diesel could emit 50% less particulate matter. However, sulphur is also needed in the current BS-IV compliant engine to make it fuel efficient. The workings were designed in a way that the sulphur is needed for the smooth working of the engine. However, the fuel efficiency may drop marginally only after a long and constant use of BS-VI fuel on a BS-IV car. The Controversy Sulphur helps the injectors in a diesel engine, thanks to its chemical lubrication properties. Low-sulphur fuels may damage and cause wear to injectors, and with damaged injectors, fuel may not reach the engine with the correct pressure through the injectors. This may lead to more unburnt fuel, subsequently contributing to more emission, bringing us back to square one. This means that engines may under-perform, while pollution remains essentially the same, bringing this entire movement and all the hype around it to moot. BS-VI-ready cars Apart from a few German luxury vehicles and Bharat-Benz trucks, no other vehicles in India are really prepared at present for switching over to BS-VI. The majority of India’s carmakers have already expressed concerns on the scale of the challenge to meet BS-VI norms in 2020. So, the rollout of mass BS-VI-compatible vehicles is doubtful when the BS-VI fuel goes on sale in 2020. In effect, the first real beneficiaries of the higher grade fuel would be cars imported from abroad that already come built to meet Euro 6 standards, courtesy technology like diesel particulate filters. To cope with the introduction of BS-VI fuel in the metro and tier-1 cities, all automakers are trying their best to launch BS-VI-ready vehicles by 2020 as well. All top automakers including Maruti Suzuki, Mahindra & Mahindra, Tata Motors, Honda and Ashok Leyland have all started the journey towards the development of BS-VI vehicles. So, the automobile market may expect a range of BS-VI-compliant vehicles to be launched by 2020. Luxury carmaker Mercedes-Benz has already launched its high-end S-Class which is BS-VI compliant. On many occasions, India's leading carmaker Maruti Suzuki has confirmed that its entire range will shift to BS-VI compliant by April 2020. Mahindra and Tata Motors are reworking their product line-up. However, many of their existing products might not see a BS-VI future. To conclude, the push for cleaner fuels is welcome but the government has to take a holistic approach as it tackles the menace of air pollution in India with an all-round development of the automobile industry to balance the changeover.