It's a scam.
Show me any reputable report of where it makes a diff.
Most gasoline has detergent additives in it with all engines pretty much fuel injected.
It's like the 93 octane scam......
I have a LS2 6.0 Corvette motor in my 2006 GTO that asks for Premium.
I run 87 or 89 and the black box adjusts the timing accordingly.
No knocking or detonation problems.....
Oh...get your oil changed every 3000 miles too...NOT
sure an ecu can retard or advance for lower grade gas
but with that you make less power..
why would you want to make less power?