That is true.ORIGINAL: Big B
This is substantially true, but I will submit from experience in the old days - running higher octane fuel in an engine than it is designed for - does in fact do some damage...though nothing permanent.
What will happen is you will foul your plugs really fast and load up the engine....aside from getting no gain in horse power...
In other words - engine performance actually will suffer.
my 2c.
But;
If I am designing an engine for 100 RON vs 142 RON, for the same displacement I can get more power out of the design for the same engine lifetime. That is what the US engineers were able to do. I can add a bit more compression (either via piston chamber and/or boost), a bit more aggressive valve timing, a bit more spark advance for the 142 RON over the 100 RON because the 142 will burn cooler (slower) than the 100 and has more energy contained within it.
Now, I can achieve very similar results by using wet Meth with my 100 RON. Again, if I know during the engine design that I am going to use wet Meth injection, I can do similar things and get very similar results.
IJ and Germany couldn't get 142 RON, so they went with wet Meth injection.
Some will immediately ask: how much more power? The answer to that lies in engine lifetime. If I am building a NHRA engine with a lifetime measured in seconds literally (like 100 secs or so) I can get 60 - 70% more power. If I am talking about a NASCAR motor with a lifetime in hours (~10), then maybe only ~30%. If I am talking about wanting 100K miles (+2000 hours), maybe ~10-15%.
I haven't built radial engines and I'm not an ex-Wright engineer. But I did read somewhere that TBolts were built for the cylinders (or sleaves?) to be replaced every 50 hours of flight time .... that would suggest when the pilot pulled the "tit" for over-boost (combat power) that they were getting very aggressive. Prolly +40% power with the 142 RON ....