Fuel prices in many parts of the country rose a total of 2 cents per litre during May, but in other areas the price rise was significantly higher as the long-running price discount war came to an abrupt end.

The price of 91 octane petrol at most outlets began the month at $2.03 per litre - the first time it had been over $2 since early December - and rose to $2.10 before falling to $2.05 by the end of the month.

Petrol is now over $2 a litre in most parts of the country. Photo: File.

Diesel prices in many of the main centres initially rose 7 cents to $1.36 per litre, before dropping to $1.31.

However, in parts of the Bay of Plenty, Auckland, Whangarei, Waikato, Hastings, Manawatu, Wanganui, Levin and Masterton - where there had previously been heavy discounts - prices at many service stations suddenly rose from below $1.90 a litre to over $2.

AA PetrolWatch spokesperson Mark Stockdale says: 'Many lucky motorists had not seen petrol prices over $2 a litre for over a year thanks to intense local price competition.

'It was sometimes more than 30 cents below the price being charged in much of the South Island and lower North Island.

'The price war came to an end during May, with Gull being the first to substantially raise prices, although in a few locations there is still some heavy discounting with the price of 91 petrol below $1.90 a litre.

'As ever, the AA advises motorists to keep a close eye on price boards and shop around for the lowest price.”

Mark says although fuel prices ultimately rose just two cents per litre during May for many motorists, the AA's monitoring shows commodity prices rose around eight cents a litre, including a drop in the exchange rate.

'The reason pump prices haven't matched the increase in commodity price increase appears to be because during the price war, fuel companies had been cross-subsidising their discounts in certain locations with higher prices elsewhere,” he adds.