Wholesale fuel prices are expected to drop from today, as new pro-competition rules begin, and it's hoped those savings will be passed on to motorists.

They include obligating fuel suppliers to publish a spot price and sell to any wholesale customers, even if they're competitors.

Restrictive terms in wholesale contracts will be limited, which will free up distributors and petrol stations to shop around for the best deal.

Z Energy Chief Executive Mike Bennetts told Mike Hosking the new contracts enable distributors to have up to 20 percent of their business with another supplier, rather than just one.

“Those agreements are now limited to a maximum of five years, so they will turn over more quickly, which should enable more competition for those agreements and those costs savings should be able to be passed on to customers.”

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