Each car has a warning signal about the low level of gas or diesel fuel in the tank. It can be a caution light, or a warning on the on-board computer. And it does not make any sense to panic, because car manufacturers have a fuel reserve.
For different vehicles the size of fuel tank reserve varies, but if you determine how many kilometers more you can drive, it is possible to calculate if you reach your favorite gas station. Usually in car documentation you can find technical characteristics of the automobile, and in the column where gasoline tank capacity is indicated, the size of reserve is shown in liters.
Auto manufacturers do not have a single fuel reserve standard. This is due to the fact that cars have different gas consumption. Usually the amount of reserve is 10-15% of the fuel tank size. But when we know approximate amount of petrol and average consumption for the last 30-50 km, we can easily calculate the distance to empty.
For example: gasoline tank capacity is 60 liters, and tank average is 8.1 liters / 100 km. Thus, we determine that the reserve is 6 liters. And given that you need 8 liters of gasoline per 100 km, we get the result: the reserve is for additional 75 km.
What to do in such situation?
The empty tank signal does not mean that you have to refuel immediately, but you don’t need to hold off until the last possible moment either. Because low gasoline level can lead to early failure of the fuel pump, and in a diesel engine, when you run out of petrol the air enters the fuel system.
You also need to take into account some factors. If you travel outside the town, and at the entrance to the city you have a warning light, and there is a lot traffic, fuel consumption will increase significantly, and will be above average.
There are websites and topics in forums where you can find information about the exact size of fuel reserve of your car. But still you shouldn’t fully trust them, because some cars of one model can have different petrol tanks, and so the size of fuel reserve will vary. At the same time petrol consumption depends on the age of the car, the more mileage, the more fuel you need per 100 km.
Therefore, when your low fuel warning light comes onit's better to top up with petrol, but do not panic and rush to the first gas station. Fuel reserve should be enough to reach your favorite petrol station.