New Delhi, July 1 -- India's automakers are challenging the government's proposal to drastically reduce vehicle emissions by 33 per cent starting in 2027-over double the pace of the current target-calling it overly ambitious and economically risky.

The Society of Indian Automobile Manufacturers (SIAM) warns that the stringent targets, part of the upcoming Corporate Average Fuel Efficiency (CAFE) Phase III norms, could trigger billions of rupees in penalties, reported Business Standard.

They argue such aggressive regulation may undermine investment in India's Rs 137-billion auto sector-a key manufacturing engine.

A key concern is the distinct treatment proposed for lighter cars versus heavier vehicles. While this split could potentially...