What changed. Russia has stopped selling diesel, petrol and jet fuel abroad, after another wave of Ukrainian drone strikes left its refineries processing less oil than at any time since 2005. America also struck Iranian rocket launchers near the Strait of Hormuz, the sea lane that carries about a fifth of the world's oil, and Brent crude has climbed back above $91 a barrel.
Your next fill. Heating oil has followed, with the UK average on our tracker up about 4p a litre overnight. A 1,000-litre fill now costs about £940, roughly £60 more than on Friday. Kerosene comes out of the same part of the refinery as diesel, so when the world is short of diesel, heating oil gets dearer with it.
The background. The story of this year is that the world has enough crude oil but not enough working refineries to turn it into fuel, first because of the war around the Strait of Hormuz and now because of the strikes on Russia. Heating oil starts September roughly three-quarters dearer than a year ago, though still about 43p a litre below the 137.6p peak reached in March.
What to watch. Two things decide where prices go from here: whether the strikes on Russia's refineries continue and how long the export ban lasts, and whether Europe can bring in enough diesel from America, India and the Middle East before the winter heating season arrives.