Excise duty revision reduces high speed diesel excise while motor spirit (petrol) is exempt under amended notification. Amendment inserts tariff entries assigning motor spirit (petrol) a nil excise rate and high speed diesel oil a reduced excise rate equal to seventy-five percent of the duty specified in the First Schedule; the change is effected under section 5A(1) of the Central Excise Act and takes effect on 30 September 2000.