Diesel set to hit 170p a litre within a week
Wed, 18 Mar 2026
Motorists are being warned that the price of diesel is on a crash course toward 170p per litre, as the fallout from the conflict in the Middle East continues to send shockwaves through UK forecourts.
Data from RAC Fuel Watch shows that diesel prices have already rocketed by nearly 20p per litre since the escalation of the conflict in Iran on February 28. As of Tuesday, March 17, the average price for a litre of diesel stood at 162.1p, with experts predicting another sharp rise within days.
The double-whammy for diesel drivers
While petrol prices have also climbed — reaching a UK average of 142.3p — diesel has been hit twice as hard. Industry analysts point to two main factors:
Crude oil surges: Brent Crude has consistently hovered above $100 a barrel, a level not seen since the 2022 energy crisis.
Strait of Hormuz disruption: As a key transit point for a fifth of the world’s oil, the current instability in the region has caused wholesale costs to spike.
"The outlook for diesel is significantly bleaker than for petrol," says RAC head of policy, Simon Williams. "Diesel appears to be on a crash course to an average price of 170p. This is really starting to hurt drivers who do high mileage, especially those who rely on diesel for work."
What it costs you
The rapid price hike means the cost of filling a standard 55-litre family car with diesel has jumped by approximately £11 in just over two weeks.
| Fuel | Feb 28 average | March 17 average | Trend forecast |
| Unleaded | 132.8p | 142.3p | Stable around 148p |
| Diesel | 142.4p | 162.1p | Rising to 170p+ |
Government response
Chancellor Rachel Reeves recently reminded fuel retailers of their "shared obligation" to keep prices fair for motorists. However, with the 5p fuel duty cut currently set to expire in August 2026, there are growing calls for the government to step in sooner to prevent a full-blown cost-of-living relapse.
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Honest John advice: How to save
Use a fuel finder: Differences between local forecourts can now be as high as 15p per litre. Check apps like PetrolPrices or myRAC before you head out.
Supermarket loyalty: Supermarket forecourts remain roughly 8p cheaper than branded sites (BP, Shell), though this gap is narrowing as they pass on wholesale costs.
Drive efficiently: AA President Edmund King suggests cutting out non-essential journeys and smoothing out your driving style to conserve what's in the tank
