Toluene & tubo/non-turbo demands
Eyelise, are you really adding a gallon of toluene to nine gallons of fuel to raise the octane? That seems a bit much, considering that there are octane boosters on the market that work and they are usually pint or quart (approx.) cans. I'm not an expert on this but have used 104+ octane booster on a '70 AMX that kept the rings intact when unleaded wasn't available in high octane. Prior to that, I turned piston rings into steel confetti one day because I used a mix of unleaded regular and leaded regular. That worked in the early days of unleaded fuel, but I learned recently that at some point in ancient history (pre 90's) additives were changed so the 'additive-effect' on octane no longer made a significant difference.
Babak, again, I am not a fuel industry expert, but have assembled a few engines (the '70 AMX a few times and a G/prod. Spitfire in the late '70's too many times!) and have learned the hard way that not only compression ratio, boosted or not, but spark advance and fuel mixture all affect the octane required to prevent detonation. Once, with the Spitfire, a distributor which had more total advance than I thought possible made the initial advance setting pretty much irrelevant and destroyed the engine in less than three laps. (it ran REAL GOOD for those 2+ laps!). I also learned with the same car, that not having the correct metering jets/needle valves/settings/etc. resulted in excessivley lean mixtures at higher RPM, again building about the same level of heat as a nuclear reactor in the combustion chamber . . . well, at least temperatures at which forged aluminum pistons melt/burn.
The prior posts stating that low performance engines do not benefit or even suffer some power loss is consistent with what I've learned. Most modern high performance engines are designed/computers programmed to deliver slightly more power with higher octane fuel. They vary as to how much effect this has, but generally, using fuel below recommended octane will lower the power output and higher octane will assure full potential is reached.