Source: BBC News, “Petrol prices rise by 5p over a week as Iran war sends oil higher”, published 9 September 2026, reporting RAC Fuel Watch data. Fuel duty figures are HMRC's own published policy paper, “Amended Fuel Duty rates: 2026 to 2027”, published 22 May 2026.
Our view
The war is pushing petrol prices up. Separately, fuel duty, cut since March 2022, is legislated to rise from 1 January 2027 unless the Chancellor extends the cut. The cut has been extended every year since 2022, but that is not guaranteed until it is announced.
Our view: plan for both rises, the one this week and the possible one in January.
What happened this week
The RAC says the average price of unleaded petrol rose 5p a litre in the space of a week — the biggest weekly increase since April — taking it to 167.17p. Diesel rose the same 5p, to 188.63p, though it remains a little below the 191.54p peak it reached in April. RAC senior policy officer Rod Dennis said: “Drivers are having to dig ever deeper into their pockets every time they fill up, and there's no sign of any relief yet.” He added that with the cost of a barrel of oil averaging $96 over the past week, “wholesale prices are surging and that's already feeding through to prices at the forecourt.”
The cause is the conflict between the US and Israel and Iran, which began at the end of February and severely disrupted crude oil supplies across the Middle East. Brent crude, the global benchmark, returned to $100 a barrel on Tuesday for the first time since July, as hostilities escalated again — US forces struck five Iranian tankers after Tehran targeted a US warship, and Yemen's Iran-backed Houthi movement attacked oil facilities in Saudi Arabia. $100 is some way below the $120 Brent hit back in April, but well above the roughly $70 it was trading at before the conflict started. This is the sharpest single-week move since April, and petrol was last this expensive at the pump in September 2022.
Illustrative family car, real published prices. The RAC says the 5p rise added £2.75 to the cost of filling a family-sized car — which, worked backwards, implies a tank of about 55 litres, in the range of a typical mid-size family hatchback.
- Full tank at this week's petrol price (167.17p): about £91.94.
- Same tank a week earlier, before the rise (162.17p): about £89.19 — the £2.75 difference RAC quoted.
- Diesel equivalent this week (188.63p): about £103.75 a tank.
If this week's price holds, a household filling up weekly pays 52 × £2.75 = £143 a year more than seven days ago.
Fuel duty from January
Fuel duty on both petrol and diesel has been held at 52.95p a litre since March 2022 — a temporary 5p-a-litre cut from the pre-2022 rate of 57.95p, extended by the Chancellor every year since. HMRC's own policy paper, published 22 May 2026, confirms that cut now runs to 31 December 2026. Unless it's extended again at Budget 2026, the legislative default takes duty to 55.95p from 1 January 2027, then to the full 57.95p from 1 March 2027 — a rise of 5p a litre in total, entirely separate from anything the oil price does.
Illustrative, on HMRC's own published duty schedule and the 55-litre tank above.
- If duty rises 3p from 1 January 2027 as legislated: about £1.65 more per fill, assuming nothing else changes.
- If duty completes its return to 57.95p from 1 March 2027: about £2.75 more per fill than today, the same as this week’s rise.
- For a weekly filler, that's another potential £143 a year, stacking on top of whatever the oil price is doing by then.
The duty rise is written into law today; whether it happens depends on a Budget decision that hasn't been made yet.
What it means for a household
If you drive a family car and fill up roughly weekly, you're already about £2.75 worse off per tank than you were on 2 September, with the RAC saying there's no sign it stops there. It comes alongside other rises this year. Check your fuel costs against your income now.
What to do this week
- Check prices before you fill up. The RAC's own advice is to use a fuel price comparison tool — its Fuel Watch page and app both show local averages — because the gap between the cheapest and priciest forecourt nearby is often bigger than a week's typical price move.
- Work out your cost per mile for your car. Take your fuel type's price above, your car's real-world mpg and your typical weekly mileage, to get a weekly figure. If commuting has become one of your biggest weekly costs, our cut your bills guide and budgeting guide help you see where it sits against everything else.
The RAC also advises driving gently, checking tyre pressures, clearing excess weight and combining short trips, which all save fuel at no cost.
What is still uncertain, and when we'll know
Nobody, including the RAC, is claiming to know when the Iran conflict eases or how much further it pushes oil prices — Dennis's own words are that there is “no sign of any relief yet.”
The fuel duty question does have a date. The government has said it will confirm final duty rates at Budget 2026, which hasn't yet been scheduled publicly. Until then, the legal default — a 3p rise from 1 January 2027 — stands. The freeze has been extended every year since 2022, but another extension is not certain until the Budget announces it.
Where coaching ends and advice begins. Working out what fuel costs you, checking prices before you fill up, and deciding whether your commute still fits your budget — that's coaching, and it's all covered above. Buzz Money Coach is a trading style of Buzz Accounting Ltd, which does not give regulated financial advice. If rising costs — fuel or anything else — are already meaning missed payments or reached-for credit, MoneyHelper, StepChange and National Debtline give free, independent help today.