Motor oil burns more rapidly than diesel. You'll get more "power" but also less durability.
Burning motor oil happens when your turbo breaks down and puts all your oil via the air inlet to your engine. It's hard to stop that engine until all the oil is used.
You absolutely can and I have before. However, I blended it 70% WMO and 30% diesel. Used motor oil WILL carbon up everything. It's so full of ash that it'll pool up internally.
You need to used a centrifuge to pull out the carbon. Sounds intense but it's not.
You can pour it entirely in your tank without any filters but your fuel filters only go to about 10-30 which will not pull out the tar. Small amounts like that won't do any damage really.
The Caterpillar diesel engine manual says you can burn up to 5% used motor oil without affecting the warrantee. It does say to make sure you filter the used oil so as not to gunk up your fuel system.
For a large engine that produces many buckets of oil at each change, this is a good way to get rid of the stuff.
Burning motor oil happens when your turbo breaks down and puts all your oil via the air inlet to your engine. It's hard to stop that engine until all the oil is used.
Didn't find an article in English, so here's a random one in Polish: https://www.autobaza.pl/page/news/choroba-szalonych-diesli-c...