Also only drive down hill and with the wind.

Dale

As for evaporation: Yes gasoline is volatile in both senses. It does evaporate quickly but it’s all captured for reuse in your engine in a charcoal canister under the hood. You also have to consider that gasoline vapor can become so thick that no more gas can evaporate and even if it did it’s in the freaking tank and you haven’t lost anything.

There is not one valid tip among these that I can see.. Are any of them provable?

As pointed out, the tanks are well insulated underground so the ambient temp does not affect them. Sure, everything is more dense when colder. I’d question if the expansion ratio is significant, or not.

Vapors. Pumping speed does not change how much gas turns into vapors. This has to do with surface area. There’s a term for this which I can’t recall, but it’s a lot like relative humidity. Close to the surface, the air is saturated with vapor and gas (or any fluid) does not want to evaporate any further. As you move away, the saturation begins to lean out and there’s a tendancy for vapors to want to distribute evenly between the higher and lower saturated regions. I would think that pumping slower would allow more time for fumes to form…

Fill when half empty because gas evaporates faster. Again, surface area hasn’t changed, but there is more air to absorb the fumes. Keep in mind that this is a closed system so these fumes are going nowhere. The counter point is just as valid, drop the extra weight by off loading non essential cargo, and fill the tank less. This will affect the rolling resistance, but then you also will be stopping more often, perhaps with short diversions from your route to refuel.

Dirt? Sorry, every pump has filters. There’s very little dirt in the tanks, and even a smaller percent could get sucked up will be filtered before going through the pump mechanisms and into your tank.

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How to Save 70c per gallon on gas