We need to let the chemical engineers get involved in the discussion.
I read somewhere that diesel and jet fuel are by products in the refining process. Since jet fuel has seen squeezed demand and lower production, then less ‘waste’ in the form of diesel is being generated.
Not sure if this makes sense….
Diesel fuel and #2 Home heating oil are almost the exact same thing chemically speaking. In fact if you run out of home heating oil, you can run down to the local filling station and fill up a jerry can with diesel.
Heating oil seasonally is at peak demand in January/February. So, that MAY have a effect on diesel prices in the winter.
Just my educated guess.
Jet fuel is basically kerosene. Comes in several grades; JP-4, 5, 6, A-1, etc.