I'm not searching for anything. I'm not the one who made that statement and don't have to back it.You can Google the gasoline of any of the fuel companies like Esso and they state on their websites that premium fuel (91 octane or greater) contain more cleaners than regular fuel and this is more appropriate for high-performance engines. Even though the 675 (with a 12.7:1 compression ratio) will run fine on 87 octane when new, IMO the premium fuel is better to use when the mileage gets higher and combustion chamber deposits build up. Holy crap, an extra buck won't even buy you a cup of coffee these days!
It's not the extra money, it's the misconception that premium fuels are somehow superior in these engines. You did not address how your magic additives somehow counteract the effect of the higher octane, and cause the charge to fully combust as it should, instead of the later, incomplete combustion that results when using higher octane fuel in an engine not designed for it.
Here's several articles to back my stance:
The Edmunds article also contains this paragraph:
Drivers used to buy a tank of premium every once in a while to clean their engines. Years ago, premium gasoline contained more detergents and other additives to stop carbon deposits. But experts say that now, because of government regulations aimed at cutting emissions, most major brands of gasoline have plenty of additives in all grades to both protect engines and cut pollution.