No science here either.
That's what I was always told as a kid. Fill the tank to keep the moisture out. And then in high school I worked as a mechanic at a landscape nursery with alot of seasonal equipment, large and small, gas and diesel. And that stuff never got parked with full tanks (intentionally anyway) or stabilized fuel.
I got on that kick the first winter at my job at the ripe age of 15 when my boss asked what I was doing that day and I was like "need to fill up all the mowers for winter storage" and he was like " The F you will. You're not spending $100 to make 50 gallons of bad gas next spring!"
Also seemed carb problems only happened to things that didn't get run out of gas or gas shut off to the carb. (Not scientific, but when you have a dozen commercial mowers to prep for the season, you kind of learn what doesn't work) And fresh gas helps start an old engine vs some cheap gas station fuel that sat for 6-8 months in effectively open to atmosphere (vented) and sometimes plastic tanks. Plastic and air are major contributors to fuel quality degradation. Part of the reason those little overpriced quart cans of happy homeowner chainsaw gas last so long.
I don't doubt that an empty tank does get some condensation under the right conditions (humidity and dew point). But thinking back, most/all fuel tanks on anything were metal and gasoline didn't contain any alcohol (unless you added it).
Metal tanks and moisture = potential/likely rust. Moisture = doesn't mix with gasoline = water in fuel system, engine dies from a slug of water or fuel line freezes.
What did they do back then for moisture in gas, add some alcohol (Heet). Either methanol or isopropyl. Yellow or red, right? And that little teeny bit of alcohol would make the water "disappear", or more accurately mix with the fuel so that it would burn and not freeze either.
Unless buying non ethanol, gas comes pre=loaded with a 1000% bigger dose of Heet than back in the day.
So the ethanol takes care of 10x the condensation as a can of Heet would theoretically.
Plus newer vehicles' fuel systems are much better sealed from atmospheric conditions, with ventless tanks.
And in the last 30 years, metal gas tanks have largely been phased out of, everything. So no rust concern either. If your rig still has a metal gas tank, filling it may be more appropriate as you should do anything you can to keep that antique gas tank in good enough condition to not have to replace it.
But even then, I just had a rusted out gas tank on the 86 GMC. It rusted out from the outside though, mud and debris trapped moisture against it. pretty sure I powerwashed dirt out of there that was at least of legal drinking age! Inside of tanks had very little to no rust in them and I guarantee the truck didn't sit with full tanks for the last 34 years. Well almost guarantee...lol Heck, it sat for at least a couple years with one tank almost empty. The PO used one tank (the bad one, it didn't leak until the pressure washer got into it) for "cheap" gas to drive around with and (said) he used a little race gas or AV gas in the other saddle tank to "run through" it before parking it for extended periods.
That's why it's largely a wives tale to "fill your tanks" before storage anymore.
Best way to maximize shelf life of gasoline is sealed from the environment in a metal container.
As that is not practical in most situations, having a small amount of "old" fuel diluted with fresh, possibly better fuel than needed IMO is better to burn than 100% "old" fuel.
And poor fuel, low octane, is tolerated better in low performance 4 stroke engines (your basic vehicles and generators). May or will get some detonation but the bad effects are not as severe as 2 stroke and high performance engines. And I'm not going to save a buck on a $3000 engine in a $7000 bike! But I can treat it the best for FREE by not having schitty gas to ever run through it.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold