Qualitative Kinetics of Combustion Reactions:

• Throw a match in a gasoline and that is all I have to say.

• Obviously the reaction is almost instantaneous, a combustion engine only injects certain amounts of fuel at a time for optimal energy to move the pistons.

• If the reaction was slow combustion engines would not work very well. 

• Here is a reference for more about kinetics of isooctane including the reaction mechanism: https://www-pls.llnl.gov/data/docs/science_and_technology/chemistry/combustion/ic8_ver3_mech.txt  (To get to sight highlight website right click and hit go to: web address)