The government on Monday hiked special additional excise duty on crude petroleum to Rs 7,100 per tonne with effect from August 15.In the last fortnightly review, windfall tax on domestically produced crude oil was set at Rs 4,250 per tonne.Besides, the Special Additional Excise Duty (SAED) or duty on export of diesel will be hiked to Rs 5.50 per litre from Re 1 per litre at present.