The shadow chancellor Ed Balls is currently making as much ground as he can out of his 'wrong time, wrong place' campaign regarding the government’s proposed 3p-a-litre rise in fuel duty next January.

He knows full well, of course, that he’s pushing on an open door as far as the rest of us are concerned – because no one WANTS to pay more for their fuel at this moment in time, even if we’re aware that we may be robbing Peter to pay Paul in the long run.

But here’s a thing; does it actually matter if the government puts the duty on fuel up by 3p a litre when you can save four times that if you’re prepared to shop around?

If you’re an HGV driver, or more to the point a haulage company to whom every mile is critical, the answer is very clearly a yes. It matters. You can’t just haul your rig off the M1 and into the local cheap garage to seek out lower priced fuel, after all.

But of you’re a car driver, it’s different. This week I’ve filled the Jaguar XK RS that I’m lucky enough to have been lent for a while twice. On both occasions the low warning light had come on, which meant there was about a gallon left in the tank, so 60 litres of space.

The first fill I did at my local garage cost £77.45 at £1.31 a litre; the second was on the M1 and cost £86.94 at £1.45 a litre.

In both cases, that gave me a range of around 250 miles. (I know, I know; the fuel consumption of the car is ridiculous and a range like that is absurd in this day and age. But in this case that’s not really the point). What is, is that I had to pay nearly a tenner more for same amount of fuel, just because I filled the car in the wrong place, at the wrong time.

Had I thought about it and worked out a way of avoiding a motorway fill (by making sure the tank was full of cheaper, local fuel when I set off, for instance) I could have saved 14p a litre.

Over 25,000 miles – which is approximately a year’s worth of driving in my world – I’d save an entire 'bag of sand' merely by going local in the XK RS. So although it might seem a touch pernickety, seeking out the cheapest fuel in a car that does 18mpg and which costs £105k in the first place, I don’t care. Because anyone who’s happy to wave goodbye to a relatively easy £1000 a year nowadays doesn’t have their head screwed on quite right.