Octane isn't something that is "IN" anything, that's like saying is there any "Richter" in an earthquake, or any "Geiger" in something radioactive, it's just a "rating" for Gasoline. Diesel you are looking for different qualities, it uses what is called a "Cetane" rating, not Octane. I'm sure an Octane number could be established for Diesel fuel, but you could do the same to turpentine, or a Coca-cola......or water for that matter.
How about "Look ma, no sparkplugs" or better yet , make it look like you don't really CARE what your mother looks at.
Gilly