A big chunk of US diesel production is exported to South America and Europe, to the tune of roughly 1 million barrels a day. I also recall reading somewhere that something like $8 billion has been sunk into new refining capacity specifically geared towards diesel and related distillates (as opposed to motor gasoline blends).
Here’s part of an explanation I once heard about why there’s so much geographical movements of refined petroleum products:
When a barrel of crude oil is refined, distillate products are produced in roughly consistent and predictable ratios. Ie, 1 barrel of crude will yield approx X gallons of gasoline, Y gallons of diesel or fuel oil, Z gallons of kerosene, etc. along with the other products of refining.
Consumption patterns vary from place to place. In most European countries, because the tax on diesel fuel can be considerably less than on gasoline (resulting in much lower prices at the pump), something like 50% or more of automobiles have diesel engines. When the local refineries have refined enough crude to satisfy the demands for diesel, they have an excess of gasoline. That’s then exported to the US. In the US, it’s the opposite - when enough crude has been refined to produce the needed amount of gasoline, there’s an excess of diesel, and so that gets exported from the US to other countries with relatively higher demand for diesel.
I’m not in the oil business, but that’s what I was once told (as a simplification) by someone who was.
except refinery processes now do all sorts of “cracking” to alter the mix of distillates. we built up around gasoline engines, so refineries went with catalytic cracking to try to get more gasoline out of each barrel of oil. European refineries tend to use hydrocracking because their demand for diesel is higher.
Diesel is usually cheaper in Europe than petrol - Cite 1 Cite 2
UK seams to do things differently to the rest of Europe.
That’s what I was going to say- basic distillation does come out with predictable ratios, but various reforming technologies like catalytic cracking (breaks heavier fractions into lighter ones) and hydrocracking (converts lighter fractions into heavier ones) can change that significantly.
IANA chemical engineer, but I’d bet that a modern refinery could tailor their processes to produce a majority of whatever they wanted.
As to why diesel’s suddenly more price competitive with gasoline… everything I’ve read points at a sluggish European economy combined with normal seasonal fluctuations (it’s more expensive in the winter, due to heating oil demand).