I'm not one to use octane boosters as I've seen the results on spark plugs, however my search to keep the OEM ECU from pulling too much timing away has got me thinking about experiementing with higher octane fuel.

Has anyone tested using different grades of octane beyond 92-93 and found measurable improvements? I guess I have to try and see for myself but that'd be butt dyno'ing so I'm wondering if anyone has any data from either a dyno session or from a OBD2 scan tool measuring the knock % or occurance getting less with better-than 92/93? I know there has to be a point where using too much octane is either wasteful or may be less beneficial if a higher % of fuel is left unburned versus normal premium fuel. Too little and the ECU may sense knock and start yanking ignition and killing power.

I know of people using aftermarket ECU's and having success with pure 100 octane or 100 octane and premium fuel mixes, but I don't recall seeing anything pertaining to OEM ECU equipped cars.