That's a new one on me...never heard that. Guess some particular recipes/brands might be able to cause problems like that, tho...

I've never stored any of my cars with anything in the tank other than fuel & air. The '74 stays in the garage under a cover, with a fan blowing under it 24/7(has for the past 10 years or so), the '85 stays outside, under a cover. Now...I will usually add a bottle of snake oil(Heet) to the tank when I take the '74 out of hibernation, just to break up some of the funk that has settled in the carb. So far so good on both of them....noc on wud....

"Heet" is grain alcohol often labled as "gas dryer" etc. Same ideal as swimmers ear and you put a drop of rubbing alcohol in her ear...it absorbs the water. Its real..it works. I have 3 small honda engines stored waaaay up in the Sierra mountains at my gold claim. They sit in plastic barrels with a full tank of gas in each. We always add stabil, run it through the system, turn the fuel off, run the carb dry and store. We have engines with 3 year old gas in them that light up on 1st pull. This is harder to do on a car unless you have an electric fuel pump but is the best way to insure bad gas does not thicken and gum up your carb. But in the big pic, sitting for 5 months is not going to be an issue for most folks. I'd just leave room for a few gallons of fresh before firing. Dilute the crappy oxygenated new fuels we all now use.
Dave