Premium petrol is expected to be easier on the wallet for motorists later this year.
The Government's acting on all Commerce Commission recommendations aiming to stop consumers paying too much for petrol.
Laws will be passed later this year to promote more wholesale competition, and change rules on display of petrol prices.
AA Principal Advisor Mark Stockdale told Mike Hosking premium price displays are likely to lead to price reductions.
"That is a positive change which motorists will notice sooner rather than later."
Price drops of up to 30c a litre are expected in some areas as a result of the changes.