The cost of petrol has fallen for the 20th time in a row following another drop in barrel prices.

A further two cents has been cut off the price of a litre by Z Energy, with the decrease taking effect nationally.

Z Energy have cut a further two cents off the price of a litre of petrol.

A litre of 91-octane is now 179.9c, and the cost of diesel has also dropped to 111.9c.

Since October last year, fuel prices have fallen by over 40 cents over 20 consecutive cuts,

The cost of diesel has also dropped by around the same amount over the same time-frame.

The barrel price of oil imported to New Zealand for petrol stood at US$56.42 earlier this month, as concerns about global supply continue to grow

Speaking to Stuff Business Day, CMC Markets New Zealand chief executive Chris Smith says the price of crude oil will continue to tumble, but a recovery is expected as the year progresses.

'In general, a lower price of oil is good for businesses and consumers,” says Chris.

'What's concerning is the political side of things that come with such a large decline.”