I’m not asking about storage, I’m asking about using high octane to run either mower.
I don’t have the push mower’s manual handy, but the rider’s manual says(the one thing I didn’t really look at) regular unleaded, and that a 10% ethanol mixture is ok. Anything higher will void my warranty.
As an aside, the manual also says to not mow wearing shorts or open toed footwear.
I had my push mower sitting for over a year without use after I ran the tank out. I put fresh gas in and it started up in less than 5 pulls It’s a self propelled Craftsman, and it doesn’t have anything I need to push before I pull the cord to start it up. I DID have a mower that I needed to push something on the side of the engine a few times before I could pull the cord; not sure what brand, or how old it was, though.