For a boost in octane rating (starting at 93), I read, adding xylene to gasoline (about 30% of the gas that you have). Is it this simple or is there more to it ?

 

 

 

 

~EE

 

It is simple, but not cheap.

Question is in the title

 

~EE

Why prefer xylene over toluene?

 

I also bought "mixed isoalkanes C9 to C11" as a solvent at a hobby market. I suspect it's the heavier fraction of the output of a refinery's alkylation unit. Then it would be very similar to avaiation gas, which has octane rating ~120.

The octane rating relates very strongly with the autoignition temperature

http://www.engineeringtoolbox.com/fuels-ignition-temperatures-d_171.html

aromatics have a high autoignition temperature, branched alkanes too, linear alkanes a low one. I don't know for sure the detailed reason.

!

Moderator Note

"What "mechanism" makes adding xylene to gasoline increase its octane rating?" (title referred to in post 3) merged with existing thread on the subject

check your pipe work and such for solvent compatibility