What happens when you drive the car low on fuel?

Some drivers aren’t exactly generous when it comes to fuel. Many drivers choose to drive the car with a low amount of fuel in the tank, believing that nothing bad can happen. First of all, there is a good chance that the fuel pump will fail, but the supply lines and injectors may also be blocked.

Many drivers prefer to drive at risk, and low fuel levels are one of them. If they are well acquainted with their car, they will be able to get to the gas station to refuel, but if they repeat the experience several times, some car parts will be damaged and the costs for the owners will not be neglected.

Here are some of them.

High fuel consumption

Not many people know that when the tank is almost empty, the car has a high consumption. But not because it would “eat” more fuel, but because the liquid left in the tank will volatilize more easily and evaporate faster. In addition, from acceleration and braking, gasoline in the tank travels more on its walls and eventually evaporates, turning into vapors that the engine can not consume. So it is best to never stay with the fuel level to a minimum because you will lose it faster.

Vapors in the fuel tank

The less fuel in the tank, the more vapors accumulate. Not for nothing, a car that has a tank filled only by a quarter will explode much stronger than one with a full tank, as shown by various TV shows. Because fuel vapors are much more flammable than the liquid itself. But this is not the only problem … Steams can cause other problems, even if they do not come in contact with any spark.

It is very easy to see if we have vapors in the tank. It is sufficient to open the tank cap, and if a rumble or whistle is heard, similar to the sound made when opening a bottle of mineral water, it is a clear signal that a pressure has been created in the tank and in the supply line, which over time it will lead to swelling and cracking of the gaskets and even cracking the tank, which results in fuel leaks, endangering the safety of the driver and passengers. So it is good to refuel more often and never let the tank empty, thus increasing the pressure in it due to the vapors.

Problems with the fuel pump

Many cars have a fuel pump in the tank. But what many people do not know is that these pumps are submersible directly into the fuel which also has a cooling role. If we drive with the tank almost empty, the fuel pump remains suspended in steam and is no longer properly cooled. This means that, over time, we may have problems with the fuel pump which will give up due to premature wear and the extra effort it has to make to pull fuel and push it into the fuel supply circuit. Here is another reason why it is not good to leave a minimum level of fuel in the tank.

Clogged circuit

Gasoline or diesel at the gas station tanks is not the cleanest in the world, especially if those tanks are almost empty and fuel is on the bottom of those huge tanks. That is also a risk because you have a high chance of filling up with fuel full of impurities, traces of rust, sediment and so on.

Obviously, these will be left at the bottom of the tank, but when it is full, you have a lower chance that they will be pulled out of the pump and put into the fuel system. The less gasoline in the tank, the more likely it is to get dirty fuel.

Even if we buy fuel from the gas stations considered to have the best fuel, it should not be neglected that, at some point, sediment, impurities, and even rust will accumulate on the walls of the tanks in which petrol or diesel is transported or stored. These will be deposited on the bottom of the car tank, and if the fuel level is always high, there are very small chances that the impurities and sediments will reach the filter in the tank and even in the petrol pump.

In contrast, if we constantly go with the tank almost empty, sediment and rust will make their way into the vehicle’s fuel system, substantially increasing the risk of blocking the supply pipes and injectors.

Running out of fuel

A reason easy to understand for everyone and often encountered is that moment when you run out of fuel in the middle of the road. Not many people realize that the fuel indicator on board is relative because it depends on a float in the tank that shows different information depending on its inclination.

So, we could be easily fooled by the dashboard indicator icon and, even if the car shows us that we still have a full quarter of a tank, we can imagine that we will only travel a few kilometers with this quarter.

Moreover, let’s say we have a state-of-the-art indicator that shows us how fair the fuel level remains in the car. If we are running with little gas, we can get into other problems: we can reach places that do not have gas stations or, in winter, we could wake up stuck in the snowy traffic and, due to the cold, we must stay with the engine started. These are unlikely situations, but possible.

Big problems in winter

If I still remember winter, the riskiest thing is to drive when it is cold with little fuel in the tank. For a few common reasons: the fuel has water in it and if we always drive with a low level of fuel, that water absorbed by the pump can freeze. That means a little fuel in the tank can lead to a high risk of frosting the fuel pump. Another risk is the accumulation of water due to the condensation resulting from the differences in temperature in winter.

For example, if we leave the car for several hours in an underground car park and outside are -15 degrees Celsius (5 degrees F), condensation is formed which turns into water vapor which eventually turns into water droplets that accumulate in the tank. In general, the idea of ​​water in fuel is not good, but if it still freezes, things can lead to serious and costly repairs.

Better to refuel more often so that we always have between a quarter and three quarters of the tank permanently filled with fuel.

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