Skipping the BS V emission norm and moving directly to BS VI emission norms for vehicles could lead to major safety compromises in vehicles. While the BS V and BS VI fuels are basically the same, the vehicular technologies are vastly different and have to be sequentially developed, tested and validated with each stage taking 4 to 4.5 years. That is also the reason why other countries have first implemented the Euro 5 norm and moved to Euro VI only after proper validation and stabilisation of the Euro V technologies, while the fuel was already available.
The danger of compressing the timeframes is the risk of putting an inadequately validated technology on the Indian roads, which will lead to safety issues in vehicles like un-intended acceleration or fires which may arise due to improper regeneration of the Particulate Trap, if the process is not adequately tested and validated in Indian Road condition. which could put the life of the consumer at risk. In such unfortunate incidents, the people of India will ask the question why the auto industry has introduced a technology on the Indian roads without proper validation and does this not amount to negligence by the industry. Industry would have no defence and the liabilities on the industry would be huge. This is not an acceptable situation for the industry.
Moving from BS III emission norms to BS V emission norms itself, improves PM emission further by upto 90% from the BS III level. Further upgradation to BS VI only offers an incremental 0-10% advantage in PM emissions, which is definitely not worth the safety risk involved in skipping the BS V stage.