If you're driving home for Christmas you'd better fill up on festive cheer - or be prepared to shop around!

Because drivers could save as much as 11p per every litre of petrol just by putting a few more miles on the clock to fill up.

Prices in the county vary widely within a very small distance, our research has shown, meaning a family could save £200 a year just by shopping around.

The difference in petrol prices between stations within a five mile radius can be anything from 5p to 11p per litre - according to petrolprices.com.

A family from Rainham driving around in a Citroen C4 Picasso with a 60 litre tank could save around £200 a year if they drove to the Sainsbury's petrol station in Hempstead Valley - selling petrol at 131.9p per litre - rather than fillng up at the Medway Services on the M2, which is just a mile away and selling petrol at 140.9p per litre.

In Herne Bay, there are potential savings of around 6p per litre if drivers look around the town.

Founder of Fair Fuel UK, Peter Carroll believes the varying prices between stations within towns shows there is a lack of transparency in the market place.

He said: "It's very hard to work out who is making money out of selling petrol and diesel and it's hard to work out who might be exploiting the fact that they're in a particular geographic location with very little competition.

"We're urging the government to have a proper commission that looks at who is making the money, why there are these huge differences between stations... to give consumers a better insight into how the market works.

"I'm a great believer in motorway services having their petrol prices shown on the motorway before you get there... right now you have to pull in and then you know what the price is.

"Consumers have got to wise up but the government should drive this and push the industry to be fairer with the public."