Work In Progress..
- '18 CX-9 Signature
It's probably a moot point since you're also paying more for premium. The octane doesn't matter so much, I think a no-ethanol fuel with good detergents is more important (but even then, it may not make that much of a difference). I use Shell 91 because its one of the very few fuels around here that contains no ethanol.I never compared but I would think you get a little better gas mileage on premium.