For use as an engine lubricant - no.
Not a good idea and why would you?
Short of re-refining it there is no good way to break the long molecules of motor oil into the size that makes diesel fuel. You can add small amounts of motor oil to diesel fuel and it will burn but it is not recommended.
Yes. The difference is that off road fuel contains purple dye. If the tractor is older you may want to add some tranmission oil to the fuel as new Low Sulpher Diesel does not lubricate as well as the older diesel. As well you can add a diesel fuel conditioner which helps restore the lubrication properties of the fuel.
somehow add more fuel
Drain the tank, change fuel filter, add correct fuel.
the black smoke is unburnt fuel. you need a leaner air/fuel mixture.
I would recommend draining the entire fuel system and re-filling it with pure diesel. I do know some guys that add a gallon or two of gasoline to their diesel trucks, meaning big rig semi's, in the winter for easier starting, however their truck's fuel tanks have a 50 gallon capacity. Diesel is a lubricant as well as a fuel. Running gasoline, or a high mixture of gasoline WILL cause SERIOUS damage to a diesel engine. So my advice would be to get it out. To add a different perspective, the Mercedes manual for the older Mercedes cars says you can safely run up to 30% regular gasoline mixed in your diesel fuel - mostly for winter, as stated above. Most diesels would be safe at near this level of mix. But at the ratios mentioned in the question looks like only a 15% mix. This should be safe, especially as a one time deal. As you run some out, just add more diesel when you can. Much better than wasting the 46 liters of fuel! Don't panic. Add a couple ounces of 2 stroke oil if it makes you feel better.
Diesel fuel itself will burn but you really can't call it flammable. When you add gasoline to it, the flammability greatly increases with the amount of gasoline you add.
Putting gas in a diesel engine will not be fixed by adding oil. The fuel needs to be drained or pumped out if the mixture is too high. If only a few liters of gasoline were put into a tank of diesel, adding a diesel fuel conditioner could help. Gasoline will damage diesel fuel pumps and injectors because it does not have the lubricating properties of diesel. The fuel pump and injectors need lubrication from the diesel fuel or they will seize up and be destroyed.
I would add fuel to the tank, and then use the fuel pump relay to prime the system. Good luck. add fuel to your fuel filter and put it back on and should start. On older diesel engines dont worry about the fuel pump relay. Add clean fresh fuel to the filter and hold the pedal to the floor while cranking and it should start.(release pedal when it starts)
add more fuel to engine witch means more power
- The easiest way is to add few liters of diesel, press and hold fully accelerator pedal and try to start the engine. It should start within 10-20 sec. - More difficult way is - open fuel filter - fill the filter right up with fresh diesel. Try to start the engine. - Safe way - Call assistance and ask to remove air from fuel system ($$$) Be aware: Fuel pomp do not like to pomp air - $$$
All that is required to restart a 2006 Cummins is to add fuel and crank the engine. The fuel system is self bleeding.