PETROL prices in the eastern region have crashed through the £4 a gallon barrier for the first time.Riddlesdell Brothers in Boxford, near Sudbury, is charging 91.

PETROL prices in the eastern region have crashed through the £4 a gallon barrier for the first time.

Riddlesdell Brothers in Boxford, near Sudbury, is charging 91.9p a litre for petrol, while prices vary wildly across the whole region.

The cheapest petrol the EADT could track down yesterdaywas 80.5p a litre at Asda in both Ipswich and Colchester.

Shopping around for petrol can make a huge impact, with savings of more than £6 to be made on the average refill, depending which pumps you visit.

Rural garages are forced to increase their prices just to stay afloat, while there are no signs that price rises at big chain outlets will slow down in the near future.

World oil prices are at their highest levels for 14 years and Chancellor Gordon Brown is also set to increase tax on petrol by 2p this September.

Simon Wooding, a spokesman for the AA in the East of England, said the price variations occur because of the cost of shipping fuel to outlying areas.

He added: "I've noticed over the last three weeks that East Anglian motorists seem to be paying a lot more for fuel than many places around the country.

"You tend to find, as a golden rule, that you get better deals in city centres and large urban dwellings because of the competition.

"If you're out in more rural areas of the county it's a captive audience and you can charge more or less what you like.

"Supermarkets still tend to have some of the best deals, but in certain parts of Suffolk you can find prices of 87-89p a litre - that is not uncommon.

"There's very little you can do about it."

Ray Holloway, director of the Petrol Retailers Association, said the difference in prices was not just isolated to Suffolk and were caused by two factors.

He added: "At the bottom end you've got extreme competition which is nothing to do with the economics of the oil industry.

"At 80p a litre, which is below cost price, they are trying to attract customers into the store.

"Meanwhile, at the top end you've got a small business in a rural area who has to contend with far fewer sales so has to charge higher prices to cover costs.

"The obvious advice to people is to shop around. However, you also have to look at the economics of driving to a different area to see if it will save you money."

Nigel Humphries, a spokesman for the Association of British Drivers, called for the planned tax increases to be shelved.

He added: "It is a bit of a petrol pump lottery - but at the end of the day it's up to people to shop around and find the best deals.

"Even at 80p a litre, there's still an enormous amount of tax in there - something like 70-80% of a gallon of fuel is tax and there's VAT on top of that as well.

"At the very least, we'd like to see some sort of move towards harmonising prices across Europe, because the Europeans pay a lot less tax."

The full extent of the petrol pump price lottery is best highlighted by prices at Tesco garages in Stowmarket, Martlesham and Newmarket.

A litre of unleaded costs 81.9p at both Stowmarket and Martlesham, but the price jumps to 83.9 in Newmarket.

A spokesman for Tesco said: "The situation with petrol is that we have a local pricing policy so we always offer the cheapest prices in the area.

"Our customers tell us that they appreciate knowing that, if they go to Tesco, it will be the cheapest petrol in the area.

"We monitor prices in the local area to make sure we are the cheapest - if we had a national pricing policy that would not be the case."

Riddlesdell Brothers declined to comment last night.

PETROL PRICES ACROSS THE REGION

Garage Unleaded Diesel

Boxford, Gulf 91.9 89.9

Brandon, Finevale 82.9 84.9

Brockford Garage 82.9 83.9

Bury St Edmunds, Jet 82.9 83.9

Bury St Edmunds, Sainsbury 80.9 82.9

Carlton Colville, Carlton Motors 83.9 83.9

Clacton, Shell 81.9 82.9

Colchester, Asda 80.5 80.9

Combs Ford, Esso, 81.9 82.9

Darsham Service Station 83.9 84.9

Felixstowe, Solar 81.9 82.9

Framlingham, Haynings 83.9 84.9

Framlingham, Potters 83.9 84.9

Fressingfield village garage 88.9 86.9

Great Barton, Total 82.9 84.9

Halesworth, Hammonds 82.9 83.9

Harleston 83.9 84.9

Harwich, Safeway 80.9 82.9

Ilketshall St Lawrence Service Station 83.9 82.9

Ipswich, Asda 80.5 80.9

Ipswich, Morrison 80.9 80.9

Ipswich, Sainsbury, Hadleigh Road 80.5 80.9

Ipswich, Sainsbury, Felixstowe Road 80.9 80.9

Kentford, Bury Road 85.9 86.9

Kessingland Service Station 81.9 82.9

Leiston, LB Shotter & Sons 83.9 83.9

Martlesham, Tesco 81.9 83.9

Newmarket, Tesco 83.9 84.9

Rivenhall, BP 83.9 84.9

Snape, Church Garage 85.9 85.9

Southwold Service Station 85.9 85.9

Stanton Service Station 83.9 84.9

Stowmarket, Tesco 81.9 83.9

Stowupland Service Station 81.9 83.9

Stratford Service Station 83.9 84.9

Troston, Jackdaw 84.9 84.9

Wangford Service Station 83.9 ------

Weybread, Cathedral Garage 86.9 83.9

All prices in pence per litre and correct as of May 27.