Average diesel prices in the United Kingdom reached 198.32p per litre on September 25, 2026, leaving the fuel just 0.77p away from surpassing the all-time high set in 2022. According to RAC data, prices have surged by 14.5p during September alone, driven by rising global oil costs and geopolitical instability.
The current record of 199.09p per litre was established on June 25, 2022. Following the rapid climb this month, the RAC suggests the benchmark is likely to be broken within days. Petrol prices have also climbed, averaging 173.6p per litre.
Rising Costs for Motorists
For drivers of a standard 55-litre family vehicle, a full tank of diesel now averages £109.08. This represents a significant increase since the beginning of the year; figures show the cost to fill a tank has risen by approximately £30 since the outbreak of conflict in Iran in February 2026.
The surge at the pump follows a rise in Brent crude oil, which hit $106 a barrel in late September.
UK Premium Compared to Europe
The price spike has resulted in the UK reaching the highest diesel price in Europe, according to market data. British motorists are currently paying approximately 12p more per litre than those in Finland and the Netherlands, which previously held some of the highest rates on the continent.
Market volatility is being further influenced by political developments in the United States. Reports indicate that Donald Trump has proposed a potential ban on U.S. diesel exports in an effort to lower domestic costs. This threat of restricted supply from one of the world’s major exporters has contributed to the upward pressure on global prices, directly impacting the rates offered at UK forecourts.
While global supply issues remain the primary driver, the gap between UK prices and those in neighboring European nations has widened, placing a disproportionate burden on British businesses and households that rely on diesel for transport and logistics.