You can drive anywhere from 30 miles to 50 miles on empty, depending on the type of car you have.
Two key factors play a role in how long you can drive your car on empty:
In general, you can expect the gas warning light to illuminate when your tank is at 10–15% capacity. So, if your car gets about 300 miles out of a tank of gas, you can probably go 30–45 miles once the gas light comes on.