We set off from the UK once in a diesel car.
The car was nothing special, just a run around for work. It was a Rover 25 2.0l diesel. Our destination was Poland via Dover UK- Dunkirk France, Belgium, Holland, Germany then Poland. Before setting off I changed the fuel filter and filled the fuel tank and the filter up with vegetable oil. At the time cooking oil was around 40 pence per liter cheaper than diesel you see. We loaded up a supermarket trolley with 90 liters of cooking oil and filled the boot of the car with it.
1800 miles or so later we arrived in Poland. We stopped at a McDonald's in Germany to fill up the car with more oil. A German man and his wife stopped dead in their tracks to watch. They were amazed. The man knowing we were English from our number plates asked me if it was cooking oil, I replied yes, he asked if the car was Scottish. You see the Germans really do get our English humor. (We call the Scottish tight or skin flints, we call the Welsh much worse lol.)
So even if Petrol - diesel was no longer produced or available, a diesel engine will run on oil. In fact even old engine oil will keep it running! The design of said engine was originally devised so that it could run on peanut oil. Diesel was the big fuel industries successful attempt to make people pay more than they really need to - to run their own vehicles.
I also put some used oil in the car that I had made chips with or French fries if you like. It ran fine, though smelt like a chip shop from behind. People sitting behind me at traffic lights must have longed for some chips when they got home without knowing why. (It is safer to let the oil settle for a few days, so any water separates from the oil.)
Use of vegetable oils as Diesel engine fuel.........
In a book titled Diesel Engines for Land and Marine Work, Diesel said that "In 1900 a small Diesel engine was exhibited by the Otto company which, on the suggestion of the French Government, was run on arachide [peanut] oil, and operated so well that very few people were aware of the fact. The motor was built for ordinary oils, and without any modification was run on vegetable oil I have recently repeated these experiments on a large scale with full success and entire confirmation of the results formerly obtained." Source of course.
Why am I writing this?
Well I take notice of things and other peoples situations. 1 of the people on here is suffering power cuts in Africa. If said person gets a diesel electric generator, then even without diesel he can stay hooked up to some electricity.
Also in the event that the lunatics that run the asylum called the world decide they want to bomb somewhere closer to home for you. You can still get around even if there was no Fiat funny money left to buy diesel.
To switch over from diesel to oil is simple with a lot of diesel engines, the Rover for instance only required a fuel filter change, to stop the filter getting blocked up with a mix of diesel and oil. Sometimes I ran it with 20% diesel and 80% oil if it was cold outside as the oil can get thicker in colder temperatures.
Additives are also available over the counter to thin down diesel when it is cold, this additive works just as well with oil.
To conclude my story I would like to add, we also returned using only sunflower oil, so we did a round trip of approximately 3600 miles on oil.