Q. What is the difference between bs4 and bs6?

Bharat Stage Emission Standards are emission regulations put forth by the government of India to regulate the output of pollutants from motor vehicles. BS6 compliant petrol vehicles are required to be 25 per cent cleaner by reducing NOx (Nitrogen Oxide) numbers from 80mg/km to 60mg/km. For diesels, the BS6 norms aims at reducing three pollutants -- HC (Hydrocarbons) + NOx, PM (Particulate Matter) and NOx reduction by 43, 68 and 82 per cent respectively. The BS6-compliant engines make use of modern technology to attain the above mentioned targets. For more details, you may check out the following article: BS4 Vs BS6: All Your Questions Answered.

The main difference in the Fzs Fi version is that Yamaha have introduced two new colours in bs6 the Darknight edition and the metalic red edition it's only the difference in Fzs Fi variant,In Fzv3 in bs4 editions underbelly cover was not present but in case of bs6 edition both fz and fzsv3 comes with underbelly cover

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