Public misconception about octane ratings has been going on for years. People think higher octane makes your car perform better, or its cleaner, or higher quality, or cleans your engine better....which is all wrong.
But of course, oil companies and gas stations won't correct you or inform you of what octane ratings mean because they want you to pay more for premium whether you need it or not.
Basically, just use whatever rating your manufacturer recommends. That's what they engineered the engine to run on so that's what you should use to make it run optimally.
Using higher than recommended does nothing for most cars because the computer won't take advantage of it. Using lower than recommended can cause problems with performance, mileage, pinging, pre-detonation, etc.
AW/Terra | ZSP | ZPP | ZCW | iDrive | CA
Mods: BC BR coilovers | Blacklines | M-tech rear | dual exhaust | M3 steering wheel | BMW SSK | ZHP shift knob | High-kick CF spoiler | NBT Retrofit
M3 front control arms | M3 rear guide rods | Manzo rear toe and camber links | Monroe rear shock mounts | Varrstoen ES1 19x9.5+20 Front, 19x11+25 rear