Diesel does not contain octane. It contains Cetane.
Octane = resistance to auto-ignite. The more there is the less likely to auto-ignite. Spark ignition engines need this so that only the spark plug lights the fire.
Cetane = ability to auto-ignite. The more there is the more likely to auto-ignite. Diesel engines need this because they rely on heat from compression (only 600F) to light the fire.
When I was a kid I put some diesel fuel into my dad's car. It wasn't much, but it WAS enough to make is run like crap...AND enough to get a beating.