Diesel is outrunning petrol again. Here is why, and what to do this week.

It has not been a quiet few weeks at the pump. Average unleaded has climbed to 158.0p a litre, which sounds high but is actually roughly par for the month. Diesel, though, has jumped to 192.1p and is still moving north. Last week alone it added 5.31p, nearly double the 3.36p rise on petrol.

If you drive a diesel and feel like the price keeps pulling away from you, you are not imagining it. Across the UK it is genuinely rising faster.

Why the gap is widening

Two things are pushing this.

The first is the Strait of Hormuz. The blockade is into its third week, and Brent crude has been trading above $112 a barrel for days. When the oil price moves, wholesale diesel reacts quicker than wholesale petrol because the refining margin on diesel is tighter to start with. So when oil climbs, diesel at the pump catches up within days. Petrol lags by a week or two.

The second reason is European diesel supply. The UK imports a meaningful chunk of its diesel from Germany, the Netherlands, and across the Med. Those flows are currently being re-routed or delayed, and any hiccup on that side shows up as extra pence at the pump here.

Put the two together and you get the gap you are seeing between the forecourt numbers for unleaded and diesel.

Where the cheap fuel actually is

The national average hides a bigger gap than most drivers realise. The average supermarket forecourt is currently selling unleaded at 155.6p, while the average branded station sits at 159.8p. That 4.2p difference comes to about £2.10 on a 50 litre fill. Across a year of weekly fills, it is real money.

The cheapest verified station in the country right now is a Co-op on Saxons Way in Halesworth, Suffolk, at 146.9p for unleaded. It is unusual to see numbers in the mid-140s anywhere at the moment, so that one is worth a flag for anyone in Suffolk. Most drivers will not have anything that cheap within range, but it is a useful reminder that prices vary a lot more than the national headlines suggest.

You can always check live prices near you on the GetCheapFuel live map within whatever radius you pick.

What is worth doing this week

Three things actually work.

One. Check before you drive, not after. A forecourt you pass five times a week is not necessarily the cheapest within a mile of your home or commute.

Two. Fill at supermarkets when the tank is below a quarter. The 4.2p saving per litre is real but not worth a detour when you still have three quarters left. Time the fills for when you need to stop anyway.

Three. If you have a 45 to 60 litre tank, even a 3p saving per litre is a couple of quid, and a 6p saving is closer to £3.50. Round trips across town for a single fill rarely pay back unless the cheap station is already on the way.

A word on the survey nobody wanted

A stat doing the rounds this week is that one in seven UK drivers have cut back on food spending to afford fuel. One in seven. The duty hike, the oil spike, and the ceasefire that has not quite held are all feeding into that, and none of them are things a single driver can fix. Finding a forecourt that is 5p cheaper will not undo any of it. But it can take the sting off the fills you make this week, which is not nothing.

The near-term outlook

The 43-day consecutive run of daily price hikes finally stalled last week. That sounds like good news but is mostly the market pausing to look at where Brent goes next. If crude starts dropping, it will take another ten days or so before supermarkets start passing cuts through. If the situation in the Gulf escalates further, diesel will take the hit first.

Worth keeping an eye on. Not worth panicking over.