Now... as to the topic at hand: I feel as though, when there is less gasoline inside the sealed gas tank, there is more air. Therefore, when there is more heat, the air heats up, and expands, at a faster rate than the gasoline. So, let us say that there is 90% hot air in the tank, with 10% fuel at the bottom. Would you not think that the gasoline, that 10%, is at a hotter temperature than the gasoline that has LESS air in the tank? Let's say, 3/4 full.. 25% air, 75% gasoline. Wouldn't that gasoline, as there is more volume and mass of gasoline, be cooler in temperature than the 10% of gas?
Now, that gasoline that is cooling the pump. Sure, it gets through there.. But, how HOT is the gasoline itself. And then, some comes through the return line.. I have begun keeping the tank refueled at 1/2 to 1/3 of empty. Today it took 11.something gallons, the video tells the tale. I try to never let that vapor get to a point where it could heat up a lot.
Also. When it gets COLD outside.. Take a gallon of water, a FULL gallon, and stick it in the freezer. Now, take one with 10% water at the bottom. Which one freezes first? The 10% one! The FULL one is still liquid, it still moves when sloshed. Thus, as well, is gasoline.
Full tanks are better, even if some fuel pumps can take being run dry and some cant. It is common sense.
