The government has increased the windfall tax on domestically produced crude oil to Rs 4,600 per tonne from Rs 3,300 per tonne, effective from Friday. The Special Additional Excise Duty (SAED) on diesel exports has been reduced to zero from Rs 1.50 per litre. The tax rates came into effect on March 1st and are part of India's effort to tax supernormal profits of energy companies.