Context: Recently, the Ministry of Road Transport and Highways (MoRTH) has issued notification for the emission norms for the L7 (Quadricycle) category for BS-VI vehicles. 
Key Points

• This notification completes the process of BS VI for all L, M and N category vehicles in India. The emission norms are in line with EU with WMTC cycle. 
• The move is likely to encourage the production of quadricycles, a segment introduced less than two years ago. The central government had introduced the quadricycle segment in 2018 and approved it for both commercial and private use. 
• Automobile manufacturers will now be able to produce petrol, diesel, CNG and biofuel quadricycles for the Indian market. 
• The Ministry of Road Transport describes quadricycle as a vehicle the size of a three-wheeler but with four tyres and fully covered like a car. "It has an engine like that of a three-wheeler. This makes it a cheap and safe mode of transport for last-mile connectivity." 

About Quadricycle Vehicle verification

• The quadricycle is a European Union vehicle category for four-wheeled microcars, which allows these vehicles to be designed to less stringent requirements when compared to regular cars.
• Quadricycles are defined by limitations in terms of weight, engine power and speed.
• There are two categories of quadricycles: light quadricycles (L6e) and heavy quadricycles (L7e).

About WMTC cycle

• The World Motorcycle Test Cycle (WMTC) is a system of driving cycles used to measure fuel consumption and emissions in motorcycles.
• The methods are stipulated as part of the Global Technical Regulation established under the UN World Forum for Harmonization of Vehicle Regulations, also known as WP.29.

About the various vehicle categories in India

• L Category Vehicles: Motor vehicles with less than four wheels [but does include light four-wheelers]. It has further seven sub-categories form L1-L7.
• M Category Vehicles: Vehicles having at least four wheels and used for the carriage of passengers (e.g., standard car with 2, 3, 4 doors). It has further three sub-categories form M1-M3.
• N Category Vehicles: Power-driven vehicles having at least four wheels and used for the carriage of goods. It has further three sub-categories form N1-N3.
• O Category Vehicles: A trailer is an unpowered vehicle towed by a powered vehicle. It is commonly used for the transport of goods and materials. It has further four sub-categories form O1-O4.
• T Category Vehicles: Agricultural and Forestry tractors
• G Category Vehicles: Off-road vehicles

How is BS-VI Different from BS-IV?

• The major difference between the existing BS-IV and forthcoming BS-VI norms is the presence of sulphur in the fuel.
• While the BS-IV fuels contain 50 parts per million (ppm) sulphur, the BS-VI grade fuel only has 10 ppm sulphur content.
• Also, the harmful NOx (nitrogen oxides) from diesel cars can be brought down by nearly 70%.
• In the petrol cars, they can be reduced by 25%.
• However, when we talk about air pollution, particulate matter like PM 2.5 and PM 10 are the most harmful components and the BS-VI will bring the cancer-causing particulate matter in diesel cars by a phenomenal 80%.