Recommended gas octane for storage?

[Bigbel07]

Hi all, storing my gt350R for the winter. Having a hard time deciding which gas to put in for storage. I have 2 options:

91 non-ethanol

93 with ethanol

What would you recommend? Would 91 non ethanol affect the longetivity of the engine possibly since it’s a lower octane? I know the manual suggests 93 but I’ve never put 91 in the car so I am afraid to do so. Feedback is appreciated!

[Gamecock]

Non-ethanol !!!

Screw the octane. The ethanol will degrade over months of storage. Sta-bil might help, but don't **** with it. Put in non-ethanol.

[daalbert]

I have three Mustangs. a 92 5.0, 08 GT500 and 18 GT350. I put the "Recreation fuel" aka ethanol free, in all for the winter plus State-bil. One tanks worth of driving in the spring will do less harm than the ethanol over the winter. 93 octane is recommended for that max HP. I am from WNY. We have 93 available. I found on a road trip west of the Mississippi with my GT350, that I could not get anything higher than 90. It worked well. I have no problems and I have almost 15k on the car.