Interesting thread this. I drive into London from Maidstone a lot, and I see a huge variation in pricing - in the main reducing the further into London I get. Locally it is about 1.37, on the A20 at Hither Green about 5p per litre less, then in Deptford about 1.30 a litre.
Don't forget that a huge number of (if not all) Shell stations are actually franchises - I am not sure how it works, however you'd think each franchisee can only negotiate their 'trade' fuel price to a small degree. Fuel is therefore a fixed cost cost to a self-employed business person who chooses, using their own judgement, what margin they make on it. As they are effectively a retail operation, you have to base any calculation of profitability on footfall per sq foot, and the cost of that sq foot in ground rent, power etc. It makes sense that a location with higher footfall potential can drop their prices on fuel a little to attract people into a reasonably large premises, especially when there is choice nearby - this is the case with the London stations I am familiar with as they are on very busy arterial routes.
At the other end of the scale, airports and motorway service stations are always expensive - possibly because rent is much higher, but probably because they have a captive customer base who have zero choice so they can get away with it. One of my local Shell stations does this I think as they are on a road which bridges the M2 and M20, both sides, so a focused, captive audience who don't want to divert into a local town for a few pence off. Thay charge more because they can. And let's face it, if it was your franchise, your business, and your livelihood, you would do the same, right ?
Just my thoughts, for what they're worth. Shell is coining it for sure, but very definitely at the expense of the franchisee - WE are being ripped off by the government first and foremost, not the forecourts.
