Originally Posted by MrLHT
Higher octane has higher resistance to detination. Meaning more cylinder pressure ( boost , static compression , more timming etc.)
Example:
Nothing is set in stone , but you could increase your total timming when running higher octane, which will increase HP.
On a 4 cylinder , I use 400 whp as a safe limit of pump (93 oct) gas, many have made more power but 93 is a little unstable with that kind of cylinder pressure.At that point 100 or higher is a good choice.
Every tuner will have what they feel safe with HP v Octane.
Hope this helps.
Additionally, in some instances depending on the fuel, engine setup etc you "could" run leaner conditions when running higher octane fuel.
Whp is not a good refference of when to run higher octane fuel because you have to factor for compression ratio & charge density etc.
It is always good to run the same "brand" fuel that your vehicle was originally tuned on due to the fact that fuels with the same octane rating from different manufacturers tend to burn differently & at times have different maximum brake torque levels.
