Factoid:
Pre war, Ukraine consumed about 450,000 barrels/day of crude (refined into diesel and gasoline).
There is a single refinery complex in Ukraine. Located at Dnipro, of which this refinery is a part. I had thought Russia would take it intact, but maybe they will destroy it.
Be aware, this is how you get fuel to a country. You send crude and it gets refined and distributed local.
Refining remote and trying to ship gasoline and diesel separate multiplies the problem several times. Dnipro is on a river that extends south to where tankers arrive. The crude comes up the river to the refinery complex.
Trying to fuel Ukraine via gas and diesel trucks from the EU looks impossible to me. That refinery complex likely decides the war.