You shouldn’t assume supermarkets will offer the lowest petrol and diesel prices

For longer than most of us can remember, the financial rules of the refuelling game at forecourts have been fair and easy to understand. In the interests of genuine and much-needed consumer choice, it has gone a bit like this…

Motorists watching the pennies have tended to shop at Sainsbury’s, Morrisons, Asda and other supermarkets where own-brand fuel has been cheapest. Drivers less concerned about prices have used traditional forecourts, where oil giants such as Esso and Shell sell generally more expensive fuels.

This is a textbook case of you pay your money and take your choice! I’ve long believed that such a consumer-friendly arrangement couldn’t be simpler.

But for the first time ever, I’m starting to question it. No longer can I, or you, assume that supermarkets will offer the lowest pump prices. I hope I’m wrong, but I fear that the rules of engagement are changing, because in the hundreds of miles I’ve driven over the past week, I’ve bought fuel everywhere from traditional forecourts to supermarkets – and it’s the latter that have got their prices horribly wrong as far as I, and my wallet, are concerned.

Examples of outlets (in the same area) I bought from, or boycotted, within a 24-hour window last week: unleaded costing 131p per litre (£5.95 a gallon) on Esso forecourts (plural) and 132p (£6.00) at a nearby Shell garage. Yet just up the road, a Sainsbury’s site demanded 135p (£6.14) and Morrisons and Asda outlets wanted 134p (£6.08).

I fear it could be the end of an era. The business model that has hitherto operated on the basis that supermarkets should offer the cheapest fuel seems broken. Great shame, that.

And before anyone argues that all this tight-fisted, penny-pinching stuff from me is unimportant in the great scheme of things, consider this: a private motorist driving 10,000 miles annually over 50 years – between the ages of 18 and 68 perhaps – will enjoy half a million miles, or thereabouts, behind the wheel. If he or she typically achieves around 40mpg and, at today’s prices, pays £7 a gallon (154 ppl) instead of the sub-£6 gallon (131p) he/she could be paying, £250 will be wasted every year. Over five decades that equates to an overspend of £12,500 – the price of a decent used premium car.

Get ripped off by being daft enough to stump up £8 per gallon (176ppl) in today’s money and you’ll needlessly overspend £500 annually or, over the course of that half-century driving life, about £25k. This is equivalent to buying a brand new Renault 5 (officially crowned The New Car World Champ 24/25) while still leaving enough change for an exotic holiday for a week or two. Crazy but true!

Yet such massive savings really are achievable for drivers who bother to do their homework and find the lowest prices – while giving those priced highest the swerve they deserve!    

Do you usually fill up with supermarket fuel? Let us know in the comments section below...