For my 2008 Kia Sedona, if I fill up immediately after the gas light is lit, I can put about 16 gallons in the tank. The manual states that the tank has a 21 gallon capacity, which means there is still the ridiculous amount of 5 gallons left in the tank. At today's prices, that's $17.50 of gas that, in theory, I'm never supposed to make use of. The most gas I've ever put in the tank in a single fill-up is 18.5 gallons. I don't want to run it all the way out of gas because of the horror stories I've heard about the fuel pump and injector damage.
I hate that the government lets the auto makers use the fuel tank's entire capacity to calculate maximum driving radius, and worse, that they are not required to disclose the importance not running the tank dry, and any potential damage that could be done if you do so.
Just want to say that my Owner's Manual for my 2010 Kia Sedona DOES warn that "running out of fuel can expose vehicle occupants to danger" and "running out of fuel could cause the engine to misfire and result in excessive loading of the catalytic converter".