I use 87 octane regular unleaded with 10% ethanol in everything.
In the fall, when I put the motorhome to bed for the winter, I put Sta-Bil in the tank (following the directions for the proper amount for 75 gallons of fuel), then run the engine and generator long enough to get it distributed throughout the system. No problems.
For my outdoor power equipment, I put Sta-Bil in the gas cans every time I fill them, so the fuel is treated all year long. Again, no problems.
The ATVs, chain saw, pressure washer, lawn tractor, air compressor, portable generator, and weed trimmer have been working fine.