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.
.Mixing a small amount of oil in the diesel fuel will not hurt a motor. The motor will run rough and produce black smoke.
Refining oil into gasoline and diesel.
Yes
#2 Fuel oil and #2 Diesel fuel are similar, however, the motor fuel will typically have lower sulfur content, and have additives to help with engine lubrication and cleanliness.
Diesel fuel is generally lighter than motor oil. Diesel typically has a density of around 0.85 to 0.87 grams per cubic centimeter, while motor oil can range from 0.85 to 0.95 grams per cubic centimeter, depending on its formulation and viscosity. Therefore, while there can be some overlap, motor oil is often heavier than diesel.
diesel is a fuel that has oil in it
No #4 diesel fuel oil is for oil burners and will not ignite in a diesel egine
There are not any calories in diesel fuel oil. Diesel fuel oil should not be consumed by humans or animals. Consumption of the fuel oil can be fatal.
In general, yes. But they've put big taxes on diesel. I have also converted an #2 oil furnace to reliably burn the motor oil from our van fleet
For use as an engine lubricant - no.
Diesel fuel is often referred to as "diesel oil" or "heavy oil". Do not confuse this with "engine oil for a diesel engine" which means "lubricating oil specially formulated for use in diesel engines". My first Ford Fiesta diesel's tax disc said - "Fuel - Heavy Oil". They've now realised that this term is anachronistic, and my latest tax disc reads "Fuel - Diesel". To be pedantic - Diesel fuel is an oil - Petrol is a spirit.
If you are talking about standard #2 diesel fuel oil and not motor oil and you have a #2 oil fired furnace or boiler in the home the answer is yes .