check out your owners manual
indicator lamp chimes and flashes 4-5 times you have about 1 gallon. when it comes on the first time , more than 1 gallon but no more than 2
In most makes, models, and years of vehicles, the low fuel gague comes on when the gas tank is 1/4 to 1/2 full. This is a good indicator that you should get gas. Also, a good rule of thumb to remember as well is this: in the winter, you should fill up your gas tank when it gets to 1/2 full.
I don't trust the "dummy" guages. I get gas when the first whistle blows that I am low on fuel.
Let's say that you have less than 50 miles to find gas.