Ford Repair: car thermostat, car thermostat, gas mileage

Question
can my truck run without the thermostat installed?  and if so, for how long?

Answer
number one what kind year make model-it can but if it is 80's or newer
gas mileage will plummet-fix whatever the reason you are removing it. because there is no good reason to take it out-if it is working probably
its ok-if not replace it-if your having a problem after that removing thermostat will just cover it up not fix it.