Cetane ???

[Drewhenry]

What is cetane? Is it to diesel what octane is to gasoline? Can you add too much?

 

[David Oxland]

Cetane is an indicator value of the ability of fuel to commence ignition promptly with out delay.

ie the the higher the Cetane # the earlier fuel will commence cumbustion at it's introduction to hot air.

In my mind kind of the reverse of Octane. Octane is that which is added to gasoline to avoid combustion when the fuel air mixture is heated.