my monster tuned with 97, running on anything below, pinging/knocking whatever u called it. but it also have shelf map that accomodate 95 if cannot find 97. fortunately it has never come across situation no 97 around.
i have seen cars with 95, 97, vpower and 100 tuning. it does make different. same car, mod, etc but on different octane. obviously each as different whp reading with right tuned map.
my islala... 95 all time, fuiyo... when 97... is like on viagra... but after all while feel the same as 95. never calculate basis mileage... no fuel just gotta pump. wanted to try 100 on it... kekekeke...