I heard you should keep your tank over 1/2 full in winter to
1. Cut down on condensation
2. Fuel pump is cooled in gasoline and low tank tends to over heat the pump.
Not true. I let my fuel level drop down to an 1/8 of a tank minimum and have never had a problem. The fuel pump overheats if you run out of gas.
Tester
Condensation is not a worry anymore with today’s sealed F.I. systems. I have never heard of the fuel pump theory,but it doesn’t seem plausible. As long as it’s pumping fuel it should be cooled by it.
The reason people recommend keeping your fuel tank over half full in winter is so you have plenty of fuel to run the engine and keep you warm in case you get stranded somewhere. There is no mechanical reason behind it. It’s a self-preservation thing.
Condensation was a problem many years ago, but is not anymore.
The gas does cool your pump, but it doesn’t need 1/2 tank. Keep it beyond the “low fuel” warning light and your pump should be safe…normally. If you live in San Francisco, you need to kepp more in there because on hills the gas may move to where the level drops below the pump pickup.
I keep mine over 1/2 tank primarily for the reasons Mark mentioned and because I’d rather always have more than I need than run out. There’s absolutely no reason NOT to keep the tank above 1/2 full. Unless you’re hyper-mileing.
Or… you don’t like stopping at the gas station more often than required.
No necessary. I like to fill my car’s gas tanks when they get to about 1/4. Sometimes a little less than that.
As long as there’s some gas in the tank the pump won’t overheat, and this is not a concern at all in winter.
If you’re driving through winter weather more gas is better than less gas, just in case you get stuck, but that’s the only reason.
Other reasons to keep tank at least 1/2 full are: A major blackout or in today’s world some kinda terrorist attack that might keep you from getting gas near your area.
Isn’t that what a siphon hose is for?? 
Personally I like to have no less than half a tank at any time. Why wait until you have less? There is some truth to the reasons offered for not allowing low fuel, but frankly I find the inconvenience of maybe running low when a fuel station is not handy a good enough reason not to let it get low. You don’t save money by not filling it up.