UK drivers have been hit with a massive £1.7bn fuel bill increase since the US-Iran conflict began just over 100 days ago, leaving average diesel motorists paying £255 more to run their cars than electric vehicle owners.

Saturday 7 June marked the 100th day of the conflict between the US and Iran, which started on the 28 February. During this time, the price of oil has increased as a result of disruptions to supply through the Strait of Hormuz, driving up the cost of petrol and diesel at the pump in the UK.

While fuel prices have dropped in recent days, latest data from the RAC shows that the average price of petrol stood at 157.93p on 8 June 2026 after peaking on 28 May at 159.53p. Petrol is 25p a litre higher than before the war. Diesel now stands at 180.92p, down from its peak of 191.54p on 15 April but still 39p higher than when the war started.

New analysis from the Energy and Climate Intelligence Unit (ECIU) has found that these price rises have added £1.7bn to the cost of running the nation’s petrol and diesel cars in the first 100 days of the US–Iran conflict. And this means that, in this time, the UK’s diesel car drivers have paid £255 more to fuel their cars than if they had been driving an EV. Recent industry data has shown an EV sales surge in the UK, mirroring Europe and other countries, as drivers try to reduce their fuel bills – more than one in four (27%) cars sold in May were electric.

Since the conflict started, petrol car drivers have paid £175 more than if they had been driving an EV. Collectively, cars running on petrol and diesel have cost over £6.3bn more to run in the last 100 days than if they had been EVs.

While automakers and even MPs continue to call for a rethink on ZEV mandate targets, Colin Walker, head of transport at the Energy and Climate Intelligence Unit (ECIU), warned that the casualty would be regular families being stuck with more expensive petrol, diesel and hybrid cars in the midst of a cost-of-living crisis.

“ The numbers speak for themselves – the savings that come from driving an EV were already significant before the war started; the closure of the Strait of Hormuz has made them even more so. EV policy has helped drive competition between manufacturers to the point where both new and second-hand EVs are cheaper than their petrol equivalents – and with pump prices high, sales are surging.

“Despite industry claims to the contrary, policy targets are being met, and any further attempts to water them down risks incentivising manufacturers to sell more PHEVs which cost more to buy than an EV, and significantly more to run that their manufacturers claim. Unlike EVs, they are not an effective answer to people’s cost-of-living concerns. Watering the targets down would also mean fewer EVs on the second-hand market where most of us buy our cars, and where regular families can save hundreds of pounds, even thousands, a year on their driving bills.”

With no clear end to the conflict in sight, if prices were to remain at their current elevated levels until the war had been running for a year, the additional costs of running the nation’s petrol and diesel cars, compared to EVs, would be over £23bn.