IF YOU are ever trapped in a conversation with someone and you don't really know what to say you will naturally drift towards similar topics of small talk.

Speaking about the weather and asking about the family are firm favourites, as of course is talking about petrol prices.

If you chose the latter as your topic of choice, the conversation will naturally drift towards where is the cheapest?

It was suggested to me that on average petrol prices in Wrexham were around 6p per litre cheaper than in neighbouring Shropshire.

So to this end I decided to quiz a selection of petrol station owners in my mission to find out the truth. A simple task you might think, but one petrol proprietors were happy to make into a challenge.

I visited several petrol stations between Oswestry and Whitchurch, visiting St Martins and Ellesmere on my travels asking managers at the stations if they believed that petrol was more expensive over the border, and if so, why?

Most stations visited were part of a larger company, including Shell and Morrisons in Oswestry and the BP.

As with all big companies staff were not too forthcoming with their opinions but I was slowly beginning to build a picture of price differences.

For example, the manager at one of the Shell garages, suggested price differences were based on area, but not why those differences existed.

And the BP manager told me that for whatever reason BP is just naturally more expensive.

It wasn't until I visited both the Texaco garages in St Martins that the actual reasoning began to become clear.

One petrol station owner suggested that according to the Texaco sales rep, Wrexham is an incredibly competitive town regarding petrol, hence why prices may seem to be cheaper.

But it was Texaco in Ellesmere that actually shed light on the situation.

Manager at Ellesmere Julie Edwards explained thoroughly the price differences across areas.

"Prices can vary quite wildly across the UK at times and are often the source of much speculation as to why," said Julie.

"Independent petrol stations, such as any Texaco site, fill up their fuel tanks in exactly the same way as you do your car, the difference being that the petrol station purchases in much larger quantities.

"The price therefore, is very much dictated by the price of the tanker the day that it is delivered and the time it takes to sell that stock through."

There are many different factors that could affect the price of petrol. Some of these are quite grand, such as the global prices of oil, but some are more mundane, such as the distance from the refinery.

"The wholesale price obviously changes daily based on Brent Crude and sold in US dollars," explained Julie

"So to put in easy terms, today's barrel price, converted into sterling gives you the price of the actual crude oil.

"Then add premiums such as refinery additives, and the government duty of 58p before adding on delivery cost, contracted margin/on cost and finally put VAT on to all of that.

"Tomorrow it will be a different rate of exchange/barrel price and so on.

Julie also says that when comparing petrol prices, the actual effort to get petrol my change the actual value for money, especially if travelling that little bit further for cheaper petrol.

"Consumer perception can play a part when comparing prices," said Julie.

"The price on the pole sign you remember from a supermarket a couple of days ago may well be gone when you get there and miles per gallon is also worth keeping an eye on as the additives used can make all the difference to performance. However, a saving is a saving right?

"Well not if you travel or queue idle to gain that extra penny or two. You can also make quite a saving over the year with a loyalty card, different fuel brands offering different rewards, which is also worth comparing."

One thing perhaps not considered, is the effect the media and global events can play on fuel prices. For example, fuel prices rose briefly last week, following the missile attack on a Saudi Arabian oil refinery.

Julie says this is a noticeable trend.

"This last few days we have seen queues at the pumps, people filling cans and had panic stricken phone calls about the "fuel situation" on the news," said Julie.

"There is plenty of supply. The cost has not gone through the roof. It's business as usual from a wholesale perspective."

All of these can begin to add up to effect fuel prices, but what about the difference between north Shropshire and Wrexham. Is fuel really cheaper across the border?

Well, maybe, but it's slightly more pragmatic than you might think.

"Clearly there is competition, the same as in any industry," said Julie.

"A place where there are multiple supermarket sites, such as a town or city centre, can be highly competitive and can sell fuel as a lost leader at times, the pole price or vouchers attracting consumers to shop in store where prices can subsidise low fuel costs."

It's as simple as that really. If you look at petrol stations in Wrexham, the vast majority are attached to a supermarket, allowing them to sell fuel at a cheaper price.

Then you have to consider the size of Wrexham and the relative density of the the town. Why would you drive across town to one station if there is another one nearby, so to be competitive the stations have to lower their prices.

Looking at it on the whole then, Wrexham is a perfect storm of cheaper fuel prices.

But for Julie, operating an independent petrol station is a vital service for smaller communities such as Ellesmere.

"Independent forecourts trade on quality and service and are very often a vital part of the local community," said Julie.

"Without single independent sites such as these, then filling up would mean quite trip each time.

"Our business is family owned and we care about our community as we live here too."