here you, yo-yo. http://www.encyclopedia.com/html/o1/octanenu.asp

an explaination even you can understand as to what the "octane rating" of
octane is.

the octane rating of normal octane, ... is, less than zero.


wtf???

That is correct. Less than zero. Less than the rating assigned to
normal heptane.

I gave you a big hint when I said to look up octane numbers for
"normal octane", "normal heptane" and "iso-octane" (a.k.a.
2,2,4-trimethyl pentane).

Here's another hint (in form of questions): which is better as diesel
fuel, octane or cetane? Which has higher octane number, heptane or
propane? Can we make any generalizations about long vs. short chain
alkanes and their branched isomers?

%mod%