Often it is the girls who ask me seemingly elementary questions, but they are important to them. One of these is how many kilometers will gasoline last if the light comes on. To be honest, I wanted to present this information for a long time, but from a slightly different side, namely, why shouldn’t you empty the car’s tank, that is, drive until it’s almost dry! In general, we read a lot of useful information...
To begin with, I would like to say that tanks have changed, they have evolved along with cars, and the point here is not in the metal tank itself (although they now have plastic ones), it’s all in its filling, namely in the method of supplying fuel.
How fuel is supplied
If we recall the recent past, namely carburetor engines, the tank often served as just a container for gasoline into which a tube was installed for pumping fuel into the system - it went to the very bottom, which made it possible to pump out fuel to the maximum. But the pumping was carried out using a special mechanical gasoline pump; it had no electrical parts at all, and it received energy from the mechanical operation of the engine. The most important thing is that the fuel pump was located on the engine, remember this!
Much water has passed under the bridge since those times; now the design has changed dramatically.
Injectors and electronic fuel supply and ignition systems have become an integral part of our lives. Nowadays there is no longer a mechanical fuel pump - it is electric and is located in the tank, and not on the engine.
If you look at this solution, then they killed two birds with one stone - firstly, there are no long lines to the pump, and secondly, they removed the overheating of the electric motor by immersing it in gasoline - after all, it gets seriously hot during operation. Afterwards, it supplies fuel to the line, and only later to the fuel rail.
What does this icon mean and why is it lit?
The icon is made in the form of a gas station, so that it is clear that you need to go there. And it lights up red, or yellow, maybe even orange - because it signals danger, namely due to low fuel level. After a certain mileage you will simply stop, so it’s urgent to “fill up” the tank.
It should be noted that in modern cars, this seems to have a double meaning, not only about low fuel levels, but also about possible breakdowns, more on that below.
About the light bulb and tolerances
Many manufacturers indicate the fuel level in the operating instructions for the car, others in the specifications on websites or dealer networks. To be honest, there is simply no single norm! It all depends on the shape of the tank and its design, but there is an unspoken standard:
Usually there is about 5 - 7 liters of fuel left, and this is enough for about 50 - 60 kilometers. It all depends on the engine size and your driving style. I would also like to note that the more you allow your car to idle, the less mileage it will have. I think this is logical.
To be honest, I measured it on my car once (I simply don’t advise you to do more, you’ll understand why later) - I have about 60 kilometers. It is also worth noting that, purely structurally, there are, as it were, two divisions on the AVEO.
The first is when “LOW” is written, one stick on the tank scale lights up, then it will last for about 70 km.
The second is when the “lamp” also lights up - then it remains for 50 kilometers.
By the way, on many cars, the inscription may light up, and not the gas station icon.
Why shouldn't you let the tank empty?
The fuel level drops, the pump tries hard to pump in the remains, its body is completely exposed and begins to heat up. This has a very negative effect on it; if you like, such overheating can cause its failure.
Remember a simple truth - do not reach a dry tank! This negatively affects the fuel pump. As soon as the light comes on, you need to immediately go to the gas station and fill up with fuel.
In a good way, make it a rule not to even reach the lamp; as soon as the fuel level has dropped, but the lamp is not yet on, we go to the gas station. Thus, the pump will always be in gasoline and cool properly.
Now we are watching a short video.
This is where I end, yes, the article is easy, but useful for beginners. Read our AUTOBLOG.
A clear belief has taken root in the automotive environment: driving with a small amount of fuel in the tank, when the minimum fuel level lamp has already come on, is harmful for the car. Drivers' rumors speak about this, car operating instructions speak about this. At the same time, there is no direct correlation, they say, since I drove with the lamp on and everything broke, and this seriously complicates the conversation on this topic - it is not known for certain what influences what and what leads to what. There are only observations and theoretical experience. But we still tried to analyze the situation and understand how harmful driving with a burning fuel light really is. To do this, let us consider the most popular arguments and evidence used by supporters of this point of view.
Fuel pump overheating
Modern injection cars use submersible pumps; they are lowered into the tank and “live” among the gasoline. It doesn’t just lie there, but is located in a special fuel module, which, among other things, includes a plastic anti-drip cup, fuel level and much more. The fuel pump itself is located inside this entire structure; during operation it generates heat, which means it must be cooled. The fuel pump does not have additional systems that remove heat (in general, it is a rather simple design), so cooling is produced by gasoline - both by what passes through the pump itself and by what floats around in the tank. If there is little fuel in the tank, heat dissipation deteriorates and the pump overheats, may become deformed and jam. Due to the increased temperature, the windings may collapse, electrical connectors may melt, in general, this is not very pleasant.
This is the most popular point of view regarding the dangers of driving a light bulb, and it is quite logical. True, for some reason it is not taken into account that even when there is little fuel in the tank, the gas pump does not run dry, it still pumps gasoline through itself. As soon as the gasoline runs out, the engine stalls, the pump stops working - this creates a kind of foolproof protection. Is the passing gasoline sufficiently cooled? Purely theoretically, yes, because the gas pump is not a very powerful unit and does not generate much heat during operation. We managed to find a couple of experiments on the Internet that confirm this point of view. But, of course, they were carried out under sterile conditions; no one measured the temperature in the tank.
Dirt and water at the bottom of the gas tank
No matter what gas stations we refuel at, as the mileage increases, particles of various impurities and water accumulate at the bottom of the gas tank, which forms in the gas tank in the form of condensate. This is an indisputable fact (in a good way, the tank needs to be cleaned periodically), but there is an opinion that when there is little gasoline in the tank, the concentration of “harmful substances” increases and the likelihood of filter clogging increases. A clogged filter does not allow fuel to pass through well, the pump is unstable and breaks down, and water can go further through the fuel system and lead to breakdowns, or even.
Dirt in the gas tank. Photo - drive
On the one hand, it sounds logical, but on the other hand, the design of the fuel intake is designed in such a way that it always takes gasoline at the very bottom of the tank, and since “harmful substances” are heavier than fuel, they will still accumulate from below, no matter how much gasoline is in the tank was. Clogged fuel module filters are certainly a problem, but it is not very clear how it is related specifically to an empty tank and driving with a light bulb. In addition, deposits appear over time and mileage, but no one says that a burning lamp is harmful only for used cars; they also do not recommend driving new ones until the last minute.
Air entry
Another theory says that when the fuel level is low The fuel pump periodically "suffices" for air, and this harms its operation, it is poorly lubricated and rubs “dry” and breaks.
It’s also logical and also not everything is clear. The presence of an anti-drip cup allows you to smooth out fluctuations in the fuel in the tank during turns, acceleration and braking; the fuel pump can start gasping for air only when the fuel is almost completely finished, but the pump will not work for a long time in this mode, if there is no fuel, the engine will stall, or even more. there shouldn't be any harm.
Here are the main three reasons that are cited as justification for the harm of driving with low fuel levels. Each of them has a sound grain, but none of them allows us to fully theoretically substantiate the problems that can arise from an empty tank. Meanwhile, drivers’ opinions and manufacturers’ recommendations still do not arise out of the blue– a lot of empirical experience has already been accumulated to notice the connection between low fuel level and failure of the fuel pump.
Not just one-off cases, but statistics say that those who constantly drive with an empty tank are more susceptible to pump failure. This is especially noticeable on cars with, their owners usually don’t fill up much, they only need gas to start - the fuel pump on such cars, according to statistics, has a shorter lifespan. It is hardly worth ignoring such statistics.
At the same time, of course, everything is individual - cars are operated in different conditions, gas pumps have different designs, the quality of fuel is also different, so it cannot be said for sure that for all cars the consequences of driving are negative to the same extent and lead to the same consequences - someone will break down after the first “light bulb”, and some people drive all their lives without problems, pouring 5-10 liters into the tank, simply because the gas pump is very durable or that’s how the cards stack up.
One thing is certain - a low level of fuel in the tank will definitely not extend the life of the car, and if you have to refuel anyway, then why not just do it more often. You won’t lose anything (after all, you still have to pay for fuel), but if something happens, you will extend the life of the gas pump. Isn’t such reasoning enough to get rid of the habit of driving “with a light bulb”?
To inform the driver about the amount of fuel in the car's tank, a fuel level indicator is installed on the dashboard. In itself, it is not particularly noticeable and, in order to eliminate the possibility of complete consumption of gasoline or diesel fuel, there is an additional warning light on the dashboard, indicated by a schematic image of a gas station.
When the light comes on, it informs you that there is critically little gasoline in the tank and that it will be enough to cover a short distance. The fuel level warning light is designed so that the driver notices in advance that there is little fuel in the tank and stops at a gas station.
The warning light can be considered a useful addition to the fuel sensor. The fact is that the sensor readings are not always accurate; there are certain errors (due to the configuration of the tank, the position of the car and a number of other factors). Therefore, the sensor may indicate an “empty” tank when it is ¼ or 1/5 full, depending on the volume of the tank (which is 10-15 liters). This can confuse the driver, since the gauge needle shows “0” both at 10 liters and at 1 liter of gasoline in the tank.
Types of indicator, principles of operation
On cars with carburetor systems, the signal lamp was powered by a potentiometric one, that is, the sensor and the lamp are connected. The principle of operation is very simple - when a certain level of gasoline is reached, the potentiometer slider connected to the float closes the lamp power contacts. At first, the contacts close intermittently (affected by the splashing of gasoline in the tank), so the indicator flashes, but with greater fuel consumption, the lamp contacts become permanently closed.
In modern cars with an injection power system, the sensor and indicator are separated. The warning light is powered by its sensor mounted on the pump housing. The main element of the signal lamp sensor is a thermistor placed in a metal flask. The principle of operation of the “lamp-sensor” circuit is based on a change in the resistance of the thermistor due to the influence of temperature.
It all works like this: voltage is applied to the thermistor, which causes it to heat up. The fuel acts as a coolant for it; it removes heat, maintaining the temperature of the sensor. If the gasoline level drops below this sensor, the temperature of the thermistor will increase, which leads to a change in its resistance. As a result of the change in resistance, the lamp lights up.
The indicator, built on the basis of a thermistor, is good because it is not connected to the fuel level sensor and works independently of it. This makes it possible to notice a decrease in fuel level even when the fuel sensor is not working.
How long can you drive with the light on?
Now let’s talk about how much gasoline remains in the tank if the lamp lights up and how long it will last. This indicator differs for different models. On average, automakers set a reserve of 100 km. That is, the light comes on if there are 5 to 10 liters of gasoline left in the tank, depending on the model. But this does not mean that after the warning light comes on, the driver will drive 100 km. The distance that can be driven on reserve gasoline is affected by driving style, road conditions, engine load, etc. That is, one driver will drive 80-90 km on reserve, while the second will only have enough time for 30-40 km. Therefore, you should not hope that you will drive a long distance on the remaining fuel in the tank. When the indicator lights up, you should immediately head towards the gas station.
How to drive if the gas light comes on
It happens that the gasoline light on the dashboard comes on, but you still have to travel a considerable distance to the gas station. And in this case, measures should be taken to ensure that the reserve is sufficient until refueling. To do this you need:
- Choose a path with a minimum number of stops. Keep in mind that 5 liters of gasoline is not enough to start the car and get to the gas station. A minimum of 10 liters is needed for the pump to fully pump the power system and ensure a stable fuel supply. If there is less gasoline, then the gas pump will “drive” air due to a lack of gasoline, which is why the engine will not be able to operate stably.
- Select a speed mode at which gasoline consumption is minimal (70-80 km/h).
- Reduce the load on the on-board network by leaving only the necessary electrical equipment turned on.
- Close the windows, position yourself behind the truck on the road, this will reduce air resistance to a minimum.
These measures will allow you to travel a longer distance on the remaining fuel.
What are the dangers of running low on gasoline?
Note that it is better not to allow the amount of fuel to decrease to the level where the warning light comes on. If for carburetor cars a small amount of fuel does not have any negative consequences, except perhaps the possibility of an unexpected stop in movement and a “walk” with a canister to the gas station, then in injection cars this phenomenon is dangerous.
The problem is that the fuel pump in such cars is placed in a tank and the fuel for it is coolant. If there is not enough gasoline, the pump motor may fail due to overheating. “Snatching” air with a pump also does not bring anything good.
Another problem is that when the level is low, the fuel pump pumps fuel “from the bottom” of the tank, where debris and dirt accumulate. This leads to a clogged fuel inlet filter, causing the pump to work under increased load, which increases the likelihood of failure.
Video: The light comes on, how long will the fuel last?
Should I worry if the low fuel warning light on the instrument panel lights up, how much longer can I drive and how can I save gas? We answer in order.
An indication of the need to refuel is usually accompanied by a single sound signal. Hear this “ding” - start counting.
It would seem, what is there to talk about? Information about the reserve in the fuel tank should be contained in the vehicle's operating manual. Or even simpler: the trip computer warns about low fuel levels and tells you how far you can drive before refueling. Not always. Others give out only dashes instead of specific numbers, causing you to panic even more.
However, the authors of instructions often limit themselves to general words. For example, “the low fuel warning light comes on when the fuel tank is almost empty.” This is a quote from the Hyundai Solaris and Kia Rio operating manuals. It even contains an element of drama: “Running out of fuel may endanger the occupants of the vehicle.” Scary…
Low fuel light is on
If you have to travel outside the city, keep a small can of fuel in the trunk just in case. Check that it closes tightly. It is more convenient when it is equipped with a watering can for refilling. Like in this illustration, for example.
Meanwhile, “drying out” is bad: you can find a lot of unpleasant adventures both for yourself and for the car. For example, burn out a fuel pump that will not have enough cooling. In addition, it will begin to pick up dirt that is in the tank of any car with high mileage. A lean mixture may damage the catalytic converter. When the engine is running at high speeds and the fuel mixture stops flowing into it (for example, in a long turn), this can lead to detonation and subsequent repairs. If it happens in a mountainous area, there is a risk of not being able to overcome the climb. And in general, any forced stop far from civilization is unsafe. In winter, you can simply freeze, afraid to leave the car. Do you think it's fiction? Alas, this happens. And not only in Siberia and the Far East, but even in central Russia. 
To reduce fuel consumption, turn off the air conditioning. This is a very power-hungry unit.
In fact, both Solaris and Rio have not so little in reserve: 7–8 liters, as the owners of such cars say. So, maybe it’s worth citing such figures after checking them first? This is quite a feasible task for the concern. Or has this horror already been removed from the instruction manual for the new Hyundai Solaris, which is about to appear on the Russian market? It will be interesting to check when we meet him.
Similar exercises are found in the instructions of three bestsellers - Renault Logan, Renault Duster, Lada Largus. Like a carbon copy: “If the lamp lights up and does not go out, you urgently need to fill the tank with fuel.” At the same time, the manual of the related Renault Sandero clearly states: “from the moment the warning light first comes on, you can drive another 50 km.”
In the instructions for the Lada Vesta there is a mention of a warning lamp, and more details should be described in the corresponding section, but the link leads to nowhere. There is not even such a section as “Vehicle Operation”. There are "Dating", "Driving", "Care" and "Practical Tips". On the contrary, Lada 4x4 has specific data (see table). The same goes for the Chevrolet Niva. Looks like a legacy from Soviet times. But the Japanese and Europeans (Germans and Czechs) are just as accurate. 
Leave Power mode until better times. Switch to Eco Mode, avoid sudden acceleration and braking.
How much gas is in the tank when the light comes on?
As you can see, in order to find the answer to the question of how long and how far you can drive “with a light bulb,” I studied the operating instructions for the most popular cars in Russia. The data was compiled into a table. Conclusion: the minimum fuel supply that car manufacturers provide us is 5 liters, in most cases it is about 7 liters. This should be enough for at least 90 kilometers when driving on a country road in a B-class car. So there is no need to panic when you see a low fuel light or a written warning that the tank is almost empty - unless, of course, you are in the tundra or desert. You'll make it to the gas station.
To find out where the nearest one is, look at the navigator map by turning on POI and filtering by gas station. No navigator - stop to use your smartphone or tablet. A short stop won't hurt. Of course, it is better to find a network gas station with high-quality gasoline, but if there is no guarantee that one is nearby, it is better not to risk it and refuel at the first one - minimally. When you get to a decent point, fill the tank full and dilute fuel of dubious quality. And wait a couple of seconds after turning on the ignition before starting the engine: let the pump fill with normal gasoline. 
A common feature of the champions in terms of efficiency (among them is the Volkswagen XL1, which consumes only a liter of fuel per 100 km) is impeccable streamlining.
We crawl, hobble in the darkness...
How to get to the gas station? Close the windows to improve aerodynamics and turn off the air conditioning if possible (air conditioning is a serious energy consumer). There's no point in turning off the music; she won't eat much. Leave the headlights on too - otherwise you will save on safety, which you cannot do, no matter what happens. You need to move as evenly as possible, without sudden acceleration and braking, in top gear, at a speed of about 80 km/h (not in populated areas). In 2008, our editor traveled to St. Petersburg and back on one tank, driving a 170-horsepower Volvo. 
Cruise control is a good tool for saving fuel. You just need to learn how to use it correctly.
To maintain a certain speed, cruise control was invented in the middle of the last century, also known as tempomat, which most cars have today. Cars with new automatic transmissions are, in principle, more economical than cars with manual transmissions - they change gears according to a certain algorithm, and not at random, and are trained primarily to conserve fuel. But even modern cars with manual transmissions (for example, Lada Vesta) have built-in “gear shift prompts” (AvtoVAZ term). And even ancient Zhiguli cars have an econometer that suggests the optimal driving mode. And in the latest generation of foreign cars, as a rule, you can select the appropriate operating mode of the power unit by pressing the Eco button. Use the maximum of available tools. If you can, check the tire pressure and adjust it to the specified pressure (the information can be found on the back of the gas filler flap or on a sign in the doorway). Are you traveling with a box on the roof and a trailer on the tail? To get to the gas station, get rid of both and pick them up when you have enough fuel.
But in general, we wish you never to see the fuel reserve light on, always fill the tank under the cap, and if you sometimes go out of town, keep at least a five-liter canister with a built-in watering can in the trunk. It is inexpensive, 500 rubles, and does not take up much space. If it closes tightly, hermetically, it doesn’t even smell. We do not recommend carrying plastic bottles with gasoline: they are more dangerous than cans. And the car burns to the ground in a couple of minutes.
One last thing: the instruction manuals are interesting reading. I recommend it. 
Page from the Lada 4×4 (ex-Niva) instruction manual. Everything is clear and extremely clear.
How much gasoline is left in the tank when the light comes on?
| brand, model | Fuel reserve as specified in the operating manual | Notes |
| Hyundai Solaris | No data, "the warning light comes on when the fuel tank is almost empty." | According to users, Solaris has at least 7 liters in reserve, which should be enough for 100 km on a country road. |
| Kia Rio | Likewise | Likewise |
| Volkswagen Polo | “It constantly burns with fuel remaining in the tank for about 80 km.” | And here, according to users, the reserve is 7–8 liters, no less than 100 km. |
| Skoda Rapid | “The warning light comes on when there is approximately less than 7 liters of fuel left in the tank” | Rapid has several powertrain options. But even in the most powerful version, the reserve should be enough for more than 100 km. |
| Renault Duster | There is no data “if the lamp lights up and does not go out, it is necessary to urgently fill the tank with fuel.” | According to the owners, a reserve of at least 7 liters (often said about 8 liters) should be enough for 90 km. |
| Renault Logan | Likewise | The reserve is about 5 liters, should be enough for 90 km. |
| Lada Largus | Likewise | Likewise |
| Renault Sandero | “From the moment the warning light first comes on, you can drive another 50 km.” | In fact, the reserve in the tank is at least 5 liters, perhaps 7. |
| Lada Granta | No data, “illuminates yellow when refueling is required to avoid engine interruptions.” | The owners claim that the reserve is about 8 liters. More than 100 km of travel! |
| Lada Kalina | Likewise | Likewise |
| Lada Vesta | No data, the corresponding item in the instruction manual could not be found. | The reserve is 7–8 liters, also for 100 km or more. |
| Lada XRAY | “From the moment the warning light first comes on, you can drive about 50 km.” | The reserve in the tank is 6–7 liters of fuel. Like Renault Sandero. |
| Lada 4×4 | “Lights up orange when there is less than 4-6.5 liters left in the fuel tank.” | "Niva", that is, Lada 4x4, is not the most economical car. The minimum consumption, according to the passport data, is 9.1 liters. per 100 km. In total, you have less than 90 km left. Alas. |
| Chevrolet Niva | Likewise | Likewise |
| Toyota Camry | “Indicates approximately 10.5 liters of fuel or less remaining.” | This reserve should be enough for another 100 km! |
| Toyota RAV4 | “Indicates that the remaining fuel is 9.0 L or less.” | The minimum fuel consumption on the highway for the version with a 2.0-liter engine is 6.3 liters per 100 km. But don’t delude yourself and take risks. Refuel as soon as possible. |
It would seem, what is there to talk about? Information about the reserve in the fuel tank should be contained in the vehicle's operating manual. Or even simpler: the trip computer warns about low fuel levels and tells you how far you can drive before refueling. Not always. Others give out only dashes instead of specific numbers, causing you to panic even more.
However, the authors of instructions often limit themselves to general words. For example, “the low fuel warning light comes on when the fuel tank is almost empty.” This is a quote from the instruction manuals. It even contains an element of drama: “Running out of fuel may endanger the occupants of the vehicle.” Scary...
What does the “light bulb” mean?
Similar exercises are found in the instructions of three bestsellers - Renault Logan, Renault Duster, Lada Largus. Like a carbon copy: “If the lamp lights up and does not go out, you urgently need to fill the tank with fuel.” At the same time, the manual of the related Renault Sandero clearly states: “from the moment the warning light first comes on, you can drive another 50 km.”
In the instructions for the Lada Vesta there is a mention of a warning lamp, and more details should be described in the corresponding section, but the link leads to nowhere. There is not even such a section as “Vehicle Operation”. There are "Dating", "Driving", "Care" and "Practical Tips". On the contrary, Lada 4x4 has specific data (see table). The same goes for the Chevrolet Niva. Looks like a legacy from Soviet times. But the Japanese and Europeans (Germans and Czechs) are just as accurate.
Stop panicking!
As you can see, in order to find the answer to the question of how long and how far you can drive “with a light bulb,” I studied the operating instructions for the most popular cars in Russia. The data was compiled into a table. Conclusion: the minimum fuel supply that car manufacturers provide us is 5 liters, in most cases it is about 7 liters. This should be enough for at least 90 kilometers when driving on a country road in a B-class car. So there is no need to panic when you see a low fuel light or a written warning that the tank is almost empty - unless, of course, you are in the tundra or desert. You'll make it to the gas station.
To find out where the nearest one is, look at the navigator map by turning on POI and filtering by gas station. No navigator - stop to use your smartphone or tablet. A short stop won't hurt. Of course, it is better to find a network gas station with high-quality gasoline, but if there is no guarantee that one is nearby, it is better not to risk it and refuel at the first one - minimally. When you get to a decent point, fill the tank full and dilute fuel of dubious quality. And wait a couple of seconds after turning on the ignition before starting the engine: let the pump fill with normal gasoline.
