I would like to start this story with a description of an incident that happened about a year ago. A client came to us at the car repair of Technohim LLP, who complained that his car had too much fuel consumption. Relatively new car, \"Toyota Camry\" with a two-liter 3S-FE engine and automatic transmission, according to the owner, "ate" too much, about 12 liters in the city. They tweaked something, measured something - everything seems to be fine. A week later, this client is with us again: “The consumption has not decreased, it has even become even worse.” Fine. Something else was replaced, something was checked and the car was sent again. But when the same car came to us either for the fourth or fifth time, I said to the owner: "Let's go for a ride with you in the evening and see." In the evening, after work, we take an empty canister, get into his car and drive to a gas station, the one on the funicular. For those who do not know, the funicular is a Vladivostok attraction and means of transportation. Fill up at the gas station full tank and a full canister, after which we drive up to the trolleybus stop (there is a flat place) and from the canister through the funnel we add the tank to the very cut of the neck.
After such refueling, I get behind the wheel, reset the daily mileage counter, and we drive to Shamora. Shamora Bay is a favorite vacation spot for Vladivostok residents. Summer, warm evening, about ten o'clock, still light. This is to give you an idea of how many cars are on the streets at this time. I must say, I was driving very economically. I didn’t press the gas pedal for more than half at all, I tried not to use the brake pedal, because. let off the gas beforehand; the windows are slightly ajar, the air conditioner is off. And we only follow the rules. It says "40" - we drive 40 km / h, it says "60" - we smoothly accelerate to sixty and drive 60 km / h. Nervousing all the drivers with our correct driving, we reached the pass in this way, we didn’t go down to Shamora, because. it was already getting dark, the headlights were turned on - and back. Just as smoothly, measuredly, just as unnerving everyone. We arrived at the “starting point”, i.e. to the trolleybus stop on the funicular, they put the car in exactly the same place from which they went on a trip, and, having opened the gas tank cap, they began to add gasoline. But not directly from the canister, but through a measuring container - plastic bottle with funnel. And again right up to the cut of the neck. After that, knowing the mileage of the car and the amount of gasoline burned, using a calculator, we calculated the fuel consumption per 100 km. When the owner of the “gluttonous” Camry saw that during our trip the fuel consumption of his car was about 7.2 liters (and this, in general, in the city), he blinked his eyes for a long time, counted again and, apologizing, had more We didn't show up at the auto repair shop. We in the brigade were ourselves surprised by such a figure, but, I repeat, I drove very smoothly, I tried not to turn the steering wheel too sharply and almost did not use the brakes. And besides, we were lucky: we did not stand in a traffic jam.
To everyone who asks what should be the fuel consumption of a particular car model, we answer with a shrug: “We don’t know. How will you ride? For example, when I go to Nakhodka alone (Nissan Maxima VG20-ET), I burn half a tank, judging by the fuel gauge on the instrument panel. I come back with my family, with my favorite animals and potatoes (the car is fully loaded) - I burn a quarter of a tank. But how do I go “there” (the tachometer needle constantly dances near the red line) and how “back” (slowly you accelerate up to 80 km / h and “saw” yourself slowly for three hours)!
So, you have a suspicion that your technically, in general, serviceable car is too “gluttonous”. The first thing to do is to replace the air filter and check the position of the arrow on the coolant temperature gauge. If the arrow is below the middle, there can be no talk of any fuel economy, such readings are already a reason to contact a car repair, especially gasoline engines fuel injected and diesel engines. After that, guided by the considerations outlined below, you should change the procedure for refueling the car, at least for a month.
Gasoline meters on dispensers that count some amount of gasoline for you have an error, which, among other things, depends on the amount of fuel being calculated. Since everything gas stations are periodically controlled by special inspections, then the mechanics, in order to avoid misunderstandings, adjust the readings of the meters in such a way that small volumes of fuel are calculated “by zeros”. This means that an inspector will arrive with a measured container, they will pour 10 liters over the counter, he will check whether this is so, and everyone is happy: there is no underflow, if there is, it is very insignificant, and maybe even a small overflow. If 30, 40 liters were measured, the picture would not be so joyful. But who will bother with a 40-liter measuring container? So there is a situation when the filling station releases small volumes correctly, and large ones - with underfilling. This was written in the magazine "Behind the wheel", we checked this fact on the seaside filling stations. Everything converges: the bay is three times 10 liters, you drive about the same as you would drive, the bay 40 liters at once.
Suppose you have done everything that is suggested above, but the fuel consumption still does not suit you. Then you should go to the center of instrumental control and measure the content of carbon monoxide (CO) in the exhaust gases in the mode idle move, at 2000 rpm and at 3000 rpm (approximately). This is necessary in order to determine whether the engine is to blame for excessive fuel consumption or not. The CO level at idle should be about 0.1% (indicated on a plate under the hood), and at speed - twice as high as the CO level at idle. If this is not the case, then you should contact the specialists, since, apparently, there are some problems with the engine or its control systems. If the level of CO is normal or less than normal, the reason increased consumption look for fuel elsewhere. These can be poorly inflated wheels (once a Nissan Safari arrived with complaints of overspending, and the pressure in the wheels was about 0.5 kg / cm2), wedged brakes, a “hole” in the fuel system, poor aerodynamics, etc. If you have a car with an automatic transmission, then remember how many revolutions the tachometer shows at a speed of 100 km / h, and contact the specialists with this information, maybe you do not have an overdrive (O / D). Now about how to avoid high fuel consumption on a serviceable car.
1. Do not buy heavy car. It is known that every 500 kg of the weight of your car consumes approximately 700 liters of gasoline per year (with a mileage rate of 20 thousand km per year). This means that if your car weighs 1000 kg, you will burn about 1400 liters of fuel per year, if it weighs 1500 kg - 2100 liters, etc.
2. Have your vehicle serviced regularly. A serviceable, but misaligned car consumes 10% more fuel.
3. Check tire pressure. More than 2/3 of motorists drive on wheels with low pressure, while it is known that a decrease in pressure from 2.0 kg/cm2 to 1.5 kg/cm2 leads to an excess of fuel consumption by about 3%. Measure the pressure in the wheels should be in their cold state. Even after not high mileage tire pressure rises.
4. Follow correct adjustment wheels ("alignment").
5. Do not carry extra cargo in the car. Every 50 kg of cargo causes an overrun of fuel by about 2%.
6. The included air conditioner increases fuel consumption by about 10%.
7. Open windows at vehicle speeds over 50 km/h also lead to excessive fuel consumption. The amount of overrun depends on how far these windows are ajar and what is the speed of the car.
8. Each deceleration implies a subsequent acceleration, which, in turn, causes increased fuel consumption. If you see that after two or three cars ahead the "feet" light up - take your foot off the accelerator pedal.
9. Do not keep your foot on the brake pedal while driving.
10. Do not hold the vehicle on a slope with the clutch and accelerator pedals. For this purpose there is hand brake.
11. Avoid travel during peak times.
12. It is better to drive slowly and smoothly than to start off and brake hard. Especially often this mistake is noticeable among drivers in "traffic jams", where they adhere to the principle: "the main thing is not to let anyone ahead of you."
13. Do not fully warm up the engine in the morning. As soon as the arrow of the temperature gauge has moved, you can go. But at the same time, the gas pedal must be pressed as little as possible, until the engine is fully warmed up.
14. Choose the right gear. In high gear, if you completely drown the gas pedal, normal acceleration will not work, and overrun - please. And as soon as you accelerate, immediately turn off the overdrive.
15. Don't drive. For cars of the 80s, fuel consumption at 110 km / h is 25% more than at 90 km / h.
16. Stop the engine when stopping for more than a minute.
17. The harder you press the gas pedal, the more fuel consumption you will have.
18. Remember! Any reduction in engine power immediately causes excessive fuel consumption.
Over the years of repairing Japanese cars, we have repeatedly had to eliminate excessive fuel consumption in Japanese cars. The reasons for this overspending were, of course, various, and here we present the most common ones.
- Faults that cause excessive fuel consumption in cars with fuel injection.
- Reduced for some reason engine power.
- The oxygen sensor or its circuit is faulty.
- One of the temperature sensors or their circuit is faulty
- Faulty ignition timing system.
- Faulty air flow sensor or its circuit.
- Faulty throttle position sensor or circuit
- Leakage of some injector (most often cold start injectors, if any).
- The air filter is clogged.
- Weak spark ignition.
- Faulty boost system.
- Incorrectly set timing drive labels.
- Faulty intake manifold pressure control system
- Wrong pressure gasoline.
- Valve clearances not adjusted.
- Bad rolling (for example due to flat tires).
- Faulty hydraulic clutch (for machines with "automatic").
- Wrong work automatic box gears.
- Faulty drive axle.
Faults that cause excessive fuel consumption in diesel cars.
- Reduced engine power.
- Defective injectors.
- Lack of air supplied to the intake manifold.
- Incorrect injection timing.
- The engine does not warm up to operating temperature.
- Incorrect operation of toxicity reduction systems.
- Reprinting is permitted only with the permission of the author and subject to the placement of a link to the source
High fuel consumption is a frequent complaint of drivers about their car.
The car, at first glance, good condition and the engine size is modest, but why such an unreasonably high fuel consumption ?!
This frequently asked question many customers of car services, including ours. Sometimes even an experienced specialist cannot unequivocally answer this question about fuel economy. Here, using our knowledge and experience, we will try to talk about the causes of this important problem for all of us.
Attention! Help for the diagnostician.
Reference books and other technical literature are offered to your attention. You will have helpful information, with the help of which you yourself can determine the causes of malfunctions and errors in the operation of components and assemblies of your car.
Content in Russian.
Format - e-books.
1. Malfunction in the electronic engine management system.
Among the many reasons for increased fuel consumption on modern cars, a malfunction of the engine management system comes to one of the first places. This is, firstly, the incorrect operation of sensors that transmit to electronic engine control unit (ECU) the main parameters of the operation of engine components.
The cause of increased fuel consumption is also affected by malfunctions of components that are not basic and necessary for the operation of the engine.
For example, the system EGR (Exhaust Gas Recirculation), which serves to reduce the emission of harmful components of fuel combustion. In the event of a malfunction EGR valve(jammed in the open state) in idle mode, the exhaust gases break into the intake manifold and sharply upset the balance of the air- fuel mixture. The ECU in such cases is not able to control the operation of the engine. With this malfunction, fuel consumption can increase markedly, especially in urban conditions, when the proportion of engine operation in idling modes and frequent gas changes is large.
Faults associated with the engine management system, without electronic diagnostics, without scanning sensors and actuators are difficult to eliminate. Finding an engine failure by replacing all of its sensors and accessories is a waste of time and money.
2. Abnormal pressure in the fuel system of the engine.
The engine ECU calculates fuel injection based on a constant setpoint. fuel pressure. When the fuel pressure is increased, the balance is disturbed air-fuel mixture towards enrichment. The situation in which the fuel pressure can be too high is quite rare, because the set fuel pressure is maintained by simple and reliable pressure regulators. But in this case, the ECU, according to the testimony oxygen sensor Re-enrichment compensates for excess fuel injection by reducing the pulse time on the injectors.
A more serious impact on fuel consumption has a reduced pressure in the fuel system. In this case, the engine power is underestimated, pressing the gas pedal only worsens the situation, acceleration dynamics worsens, the ECU is not able to compensate for the lack of fuel due to even the maximum fuel injection pulse time. In addition, with wide open throttle the vacuum falls in intake manifold- it means that the air flow sensors give an overestimated engine load signal that does not correspond to reality. This leads to a final drop in engine power.
If the car is equipped with an automatic transmission, then the operating time for low gears increases, the engine runs longer at higher speeds (efficiency decreases), hence the high fuel consumption.
3. Faulty engine injectors.
Operated without preventive maintenance, dirty engine injectors are one of the most common causes of increased fuel consumption.
Due to the violation of the shape of the spray jet and the quality of the fuel spray, normal mixture formation is disrupted, as a result of which we have a decrease in efficiency: the engine “troits”, a significant part of the fuel “burns out” uselessly in the exhaust manifold and catalyst of the car, reducing its service life .
With contaminated injectors, the acceleration dynamics of the car deteriorates sharply, the gearshift modes are delayed, the engine runs at high speeds for a long time, and fuel consumption increases.
Conditions are created under which the load on high-voltage parts of engine ignition systems increases: candles, high-voltage wires, ignition coils, electronic distributors, which leads to their damage or a sharp decrease in their useful life.
Our recommendations - periodically do preventive cleaning of injectors, this is one of the important ways to save fuel.
Read about methods of cleaning injectors on the website www.rat-auto.ru
Read more about the consequences of running an engine with dirty injectors.
4. Failure of the catalytic reactor (catalyst).
Burnt and destroyed catalyst - the reason sharp decline engine power and very high fuel consumption.
With a high resistance to exhaust gases, the balance of the air-fuel mixture is sharply disturbed in the direction of re-enrichment, because. with a small vacuum in the intake manifold, the engine control unit analyzes a large load and increases the open time of the injectors.
An avalanche-like process occurs - the more the catalyst is "clogged", the richer the mixture, the more the catalyst overheats and collapses.
Reasons for the destruction of the catalyst:
- Usage low-quality gasoline.
- Rarely serviced, dirty engine injectors.
- Old or damaged spark plugs.
- Malfunctions in the engine management system and automatic transmission.
5. Clogged air filter.
Everyone knows this reason, but for some reason, many people forget to replace the air filter in time. With a clogged air filter, we not only get the effect of "air starvation", but, more importantly, the correct operation of the intake air flow sensors (MAP, MAF, etc.) is disrupted.
The ECU erroneously calculates the engine load, respectively, mixture formation occurs incorrectly. Increased fuel consumption is inevitable.
6. Influence of faults automatic transmission.
The automatic transmission torque converter is equipped with a lock-up clutch ( TCC), which is triggered by a signal from the automatic transmission control unit.
In lock mode, the rotation speed of the automatic transmission input shaft is compared with the rotation speed crankshaft engine. At the same time, there is no slippage in the torque converter, the engine speed decreases, and fuel consumption also decreases.
The absence of the torque converter blocking mode is always an increased fuel consumption with an apparent normal operation of the car, as well as overheating of the automatic transmission.
The electronic control systems of many automatic transmission models, in the event of malfunctions in the torque converter blocking unit, also prohibit the transition to overdrive gear, that is, the most economical gear will be absent in the car.
Modern automatic transmissions with electronic control in case of critical malfunctions, they switch to emergency operation mode ( limp-in), which protects the transmission from further damage. In some models, this mode includes only 2nd gear, in others only 3rd gear.
Some inexperienced drivers, instead of timely diagnosis of automatic transmission, continue to operate the car in emergency mode, This leads to huge expense fuel.
7. Driving style and fuel economy.
The basic principle of economical driving is to quickly shift to a higher gear and use coasting (coasting).
If your vehicle is equipped with cruise control ( Speed control or cruise control), take a closer look at the algorithm of operation of such systems. This fast acceleration to top gear, deceleration and coasting. If you compare fuel consumption in the "Speed Control" mode and in your own driving style, then some motorists will be the loser.
Some drivers who changed the car from a manual transmission to an automatic did not change their driving style, that is, they continue to "work" with both feet, but under the left foot there is not a clutch pedal, but a brake!
Such drivers certainly complain about increased fuel consumption.
8. Influence of car air conditioners on fuel consumption.
Consider two cases: operation in urban driving and on the highway. In urban mode, where the engine idle time is long, the air conditioner takes part of the engine power to work the compressor. Moreover, than weaker engine, the greater the share of the power take-off goes to the operation of the air conditioner. Usually on idling it is from 5% to 15%.
In engine operating mode high speeds and loads (on the highway), the effect of air conditioning on fuel consumption is hardly noticeable. In these operating modes, the engine power is high and part of the power spent on the operation of the air conditioning compressor can be neglected. When the air conditioner is running, the windows of the car are usually closed, which improves aerodynamics and has a positive effect on fuel consumption.
9. Viscosity of lubricating oils and fuel consumption.
Wrong choice of viscosity parameters for engine oils, gearboxes, transfer box, drive axles, of course, greatly affects fuel economy. The use of oils with unreasonably high viscosity characteristics can increase fuel consumption by 10-15%.
10. Influence of engine operating temperature on fuel consumption.
Optimal working temperature engine - 97-104 °
WITH.
When the engine overheats, the balance of the air-fuel mixture is disturbed, the mixture becomes discharged due to overheated intake air and rapidly evaporating fuel. The filling of the engine cylinders under these conditions is poor: the engine runs on a lean mixture, detonation ignition appears and sudden loss power. These conditions lead to further engine overheating and increased fuel consumption.
- The main causes of engine overheating:
- Thermostat stuck closed.
- Water pump malfunction.
- Loose or damaged engine radiator cap.
- Dirty engine radiator or scale build-up inside the radiator and engine cooling ducts.
- Radiator cooling fan failure.
In cold engine conditions, the ECU program calculates rich fuel injection, this is necessary for stable operation in warm-up mode. If the engine temperature is below operating temperature, the ECU continues to control the quality of the air-fuel mixture according to the engine warm-up algorithm. For example, at temperatures below 80 °
With fuel consumption can increase by 15-20% more than the nominal. The cause of a low engine temperature is usually the absence of a thermostat or a faulty (loosely closed) engine thermostat.
There is another reason for increased fuel consumption due to low engine temperature - this is the constant operation of the car for short distances. If the driver uses the car to get to the place of work in 3 km. home and back, the engine will never reach operating temperature.
11. Wrong choice of wheel size.
Any design of automatic transmission is designed taking into account the operation of a car with a certain type and size of wheels. Hydraulics, kinematics and electronic system automatic transmission control will only work optimally with the recommended type and size of wheels. Violation of this requirement leads to a natural result - increased fuel consumption.
Some modern electronic transmissions (for example, Chrysler 41TE, 42LE, 45RFE) have an adaptation mode (quick learn), which allows you to optimize the automatic transmission control depending on its hydromechanical characteristics and adaptation to a given wheel size (pinion factor). But if on a regular a car wheels from an SUV are installed, then no miracles of modern electronics will save you from excessive fuel consumption.
The reason for the high fuel consumption often lies on the surface- it is enough to make a competent diagnosis of the engine, but sometimes there is a complex of malfunctions associated with various nodes and vehicle units, each of which contributes its share of errors to the overall vague picture of unreasonably high fuel consumption.
If in such a situation you have to contact any car service with the problem of excessive fuel consumption, do not immediately blame the specialists for incompetence, they will not be able to accurately determine its cause in one session of electronic diagnostics.
Sometimes the problem of increased fuel consumption can only be solved in stages, removing errors in each faulty node car, please be patient.
Many factors affect fuel consumption. First of all, these are aerodynamics, power and engine thrust on low revs, as well as the resistance of the road surface. A lot of energy is spent on acceleration to cruising speeds, but then the force is spent solely on overcoming the resistance of the environment. Therefore, in order to reduce emissions harmful substances from exhaust pipe environmentalists recommend resorting to a simple mechanism for handling the gas pedal. You can press it only at the start, but after a speed of 30 km / h, light touches are enough. Then the engine will not spin up over 2500 rpm. And this is quite enough for life in the city.
Modern motors have good characteristics on the bottoms. Thanks to direct injection manages to reach 80% of torque at 1200 rpm. If the engine is also equipped with a variable valve timing system, then 80% of thrust is available even from 1000 rpm. And this means that for a smooth start and acceleration it is not required to gas. By the way, according to the standards of the average European cycle, acceleration to “hundreds” is carried out in 30 seconds, and such dynamics just occurs within the boundaries of 2000 revolutions.Keeping the engine from over-revving is not easy. If the vehicle is equipped with a manual mechanical box gears, you can smoothly release the pedal already at idle, and the motor equipped electronic injection, he will slightly raise the thrust so as not to stall. On new BMW models and MINI already has a driverless start system. In order to avoid unnecessary regassing, the electronics itself exposes correct level fuel supply.
The higher the better
But then you need to reach the highest gear as quickly as possible. At a speed of 30 km / h, it is necessary to turn on the fourth stage, and at 60 km / h, it is necessary to set the “sixth”. Then the engine will spin below 2000 rpm, fuel consumption will drop significantly. For example, at 3 thousand revolutions, 3.5 times more fuel is consumed than at 1500 revolutions.
Thus, driving at a speed of 50-60 km / h for top gear will reduce the consumption of a 1.6-liter engine to 4-5 liters per "hundred". This technique is useful when the fuel level is zero, when you need to reach the nearest gas station with all your might.
Besides, modern cars use the "Start-Stop" system, which automatically turns off the engine at forced stops. On the "old women" you can turn off the engine yourself. Standing in traffic jams and in front of traffic lights without a working power unit gives a total of another 5% fuel savings. But here we must remember that frequent starts harm the mechanics, and it is better to turn off the engine at stops lasting more than one minute.
Tires and aerodynamics
Well-inflated tires help save fuel. Many manufacturers under standard conditions recommend inflating the “front” to 2.2 bar, and the rear wheels to 2.3 bar. This is the most comfortable pressure for R16 and R17 wheels. But many do not follow the tires for months, allow pressure to be released and forget that the tire sags on a loaded car, increasing the contact patch, which leads to increased wear and increased fuel consumption. Therefore, to travel with the family to the country with a simple belongings in the trunk, you need to increase the pressure in the tires. Each car model and wheel size has its own value. For example, on Focus II with 205/55 R 17 wheels, it is recommended to run in rear tires 2.8 bar. And at Ford Mondeo rear wheels 215/50 R 17 recommend pumping up to 2.9 bar. Then the contact patch of the wheels with the asphalt straightens up to standard values and will decrease by about 1.5 times compared to the minimum pressure threshold. As a result, rolling resistance on asphalt will decrease. And this is about 10% fuel savings. But before pumping the wheels, you need to look at the instructions.
"Recommended for specific car pressure can be found on special stickers, which are usually located on the gas tank flap, in the doorway or on the glove compartment, says the head of the promotion team trademark and internal communications of Nokian Tiers LLC Alexey Zayakin . “Following the automaker’s recommendations will have a positive impact on tire performance: grip, hydroplaning resistance, fuel efficiency and tire mileage.”
But most importantly, in order to avoid an increase in fuel consumption, the aerodynamics of the car must not be violated. A roof rack, ridiculous sports body kits and collective farm rear wings can significantly distort the passage of air flow through the car body. Turbulent eddies appear behind the stern, a zone is formed reduced pressure, which sucks the car back, preventing its movement. Now all cars are blown in wind tunnels, where engineers are trying to arrange the body so that the air flow is dumped and chaotic already far astern. The sedan is considered the most optimal body type in terms of aerodynamics.
In general, these simple tips can help save on gasoline. Tests of domestic magazines have shown that thanks to a set of these rules, it is possible to reduce the consumption of a 1.6-liter atmospheric motor on C-class cars with a manual gearbox and front-wheel drive up to 3.5-4 liters of gasoline per 100 kilometers. True, driving so economically is a lot of work.
Many car owners are interested in the issue associated with high fuel consumption. There are reasons for fuel consumption, some of them are done by the person himself, and some of them are manifested in connection with the failure of the units of the unit.
The reasons for increased fuel consumption can be divided into two groups. In the first, the fault lies with the vehicle - the reason lies in any mechanical failures. And in the second, the driver who made some mistakes or deliberately created difficult operating conditions for the car is responsible for the growth in the consumption of gasoline or diesel fuel.
Driver mistakes that increase fuel consumption
There are several typical mistakes that inexperienced drivers make, leading to excessive fuel consumption. Remember that the excess amount of gasoline or diesel fuel will be consumed when:
- Operation of the air conditioner or climate control system. The operation of these devices is associated with the operation of the compressor. Indeed, to rotate the pump pulley, energy is needed, which is taken from the rotating crankshaft. And it requires additional fuel.
- work heating system . This applies not only to the operation of the "stove", but also to the heating of seats, windows and mirrors (in cars where these options are provided). The logic here is similar to the situation described above.
- Sharp acceleration. If you like to pull away hard at traffic lights or other places, then be prepared for the fact that your car will use more fuel than usual. This is due to the fact that any transient process (in this case driving the machine) is associated with increased energy consumption. And the sharper it is, the more energy is needed. Therefore, try to move smoothly. So you not only save fuel, but also save tires, clutch and powertrain components.
- Engine operation at high speeds. Try not to overdo it. This will not only save fuel for your car, but will also have a positive effect on the operation of the engine as a whole.
- use low-quality fuel . Try to refuel at proven gas stations and fill the tank with the brand of fuel that is recommended by the automaker. After all bad fuel burns worse, gives an insufficient amount of energy and requires additional energy costs.
There are also a number of objective reasons why a car consumes more fuel than prescribed. All of them are connected with the state of its individual components and mechanisms.
Technical reasons for the increase in fuel consumption
To begin with, let's deal with technical problems, which contribute to an increase in gasoline consumption in a car. Let's find out the most common causes associated with the engine and other elements, due to which the consumption increases.
Fuel Consumption Factors
#1 Engine Wear
Usually occurs due to the high mileage of the car or its improper operation. Some points related to the operation of the engine:
- the temperature of the coolant (coolant) is lower than calculated;
- wear ;
- wear of the crank mechanism;
- wear of the gas distribution mechanism and unadjusted valve clearances.
Engine wear is one of the critical factors increase in fuel consumption.
#2 Clutch wear
When the driver needs to keep high speeds in order to move off and shift to a higher gear, this directly affects fuel consumption. In this case, replacing the clutch will help.
One of the reasons for increased fuel consumption is the wear of the clutch disc. The situation here is quite simple. The engine consumes more fuel during starting than at constant speed. This fact is present even with a good clutch. If the disk or other parts of the system are faulty, then it turns out that the fuel is consumed, and the car stands still. The more often the car starts off, the greater the excess fuel consumption takes place.
In critical cases, a similar situation can occur even when driving in constant mode. That is, when the clutch disc does not provide synchronous rotation of the engine and gearbox. This situation, although rare, can happen in the most "neglected" cases.
Diagnosing clutch wear is fairly simple. To do this, you need to put the car on the handbrake, turn on fifth or fourth gear (depending on the gearbox, that is, the highest) and try to move off. If at the same time you did not turn off the engine with gas, this means that the clutch needs to be repaired or completely changed.
#3 Ignition set incorrectly
An incorrectly set ignition is also the cause of increased fuel consumption. In particular, if the engine "troits", then gasoline from idle cylinder emitted directly into the exhaust system. This leads not only to excessive fuel consumption, but also to increased wear catalyst.
If the ignition is simply set incorrectly, then a situation arises when the fuel does not completely burn out. That is, a spark occurs before the fuel mixture appears in the cylinder in full, or after. In any case, this leads to its incomplete combustion. And this automatically means that the fuel is wasted.
Therefore, always monitor the condition of the ignition system. The amount of fuel consumed directly depends on this. In addition, an incorrectly set ignition system can cause problems when starting the engine.
If either the pressure in them is less than normal, then this will also lead to the fact that the car will start to “eat” more than it should. In such a situation, it is necessary to replace the tires, and regularly check the tire pressure.
With a wide tread, they create increased resistance, and, accordingly, increased fuel consumption.
Car tire wear affects not only fuel consumption, but also handling. Keep track of tire tread depth.
#5 Brake system problems
They are different, consider those that lead to incomplete unclenching of the calipers when the so-called “wedging” occurs. If the caliper is not completely unclenched, then over time, not only brake pads but also discs. Due to excessive friction and resistance, fuel consumption naturally increases.
#6 Failed Spark Plugs
Through unsuitable candles, the car does not work correctly, as a result - an additional load on the engine. This leads not only to the fact that there is a large fuel consumption, but also to a general deterioration in performance. To avoid, it is necessary to check the candles.
This includes examining the color of soot, measuring the electrode gap, checking the resistor for breakdown. It is also worth paying attention to the junction of the white insulator to the threaded part of the candle - a red coating is unacceptable.
It is necessary to monitor the condition of the spark plugs.
#7 Clogged jets or carburetor
Clogged injectors are one of the most common causes of wasted fuel. They clog due to natural causes. These are the use of low-quality gasoline, Not timely replacement fuel filter, dirt getting into engine compartment and so on.
With clogged nozzles, a violation of the shape of the fuel spray jet in the combustion chamber occurs. Because of this, the formation of the fuel mixture is disrupted. That is, this process uses large quantity gasoline than needed under normal conditions.
In some cases, due to clogged injectors, the engine may start to “troit”. This is reflected in the reduction dynamic characteristics car. It is also possible to run the engine for a long time at high speeds, even at idle. This in itself leads to an increase in fuel consumption.
Similar reasoning is valid for machines with carbureted engine. When the carburetor is clogged, the same situation arises with excessive consumption of gasoline and a drop in dynamic performance.
So always be on the lookout fuel system, in particular, nozzles on an injection engine and a carburetor on a carburetor. Their clogging is a direct cause of excessive fuel consumption.
Low-octane fuel also has a great effect on consumption (for low price and poor quality is accounted for by quantity).
Fuel supply to the engine cylinders and consumption depends on the condition of the fuel equipment.
#8 Breakdown of the lambda probe or DMRV
The failure of the oxygen sensor () can also lead to a significant waste of fuel. Its task is to control the amount of oxygen that goes into the fuel mixture. Therefore, if this sensor is faulty, the mixture will not be created correctly, and this will lead to excessive fuel consumption.
The lambda probe is quite fragile. There are a number of reasons why it might fail. Among them:
- depressurization of its body and penetration into its exhaust gases;
- overheating of the sensor (this may be caused by incorrect operation of the ignition system);
- natural aging and wear;
- problems with the car's electrical network;
- mechanical damage to the sensor.
Similar reasoning is valid for the sensor mass flow air(). It is designed to regulate the level of air supply to the engine cylinders. Sensor failures are easy to identify. As a rule, in this case, the engine starts to work unstably, especially at idle (very high or low “jumping” speed), loss of dynamic characteristics (the car accelerates poorly). The mass air flow sensor is beyond repair. It can only be replaced, although cleaning it can temporarily fix the situation.
Only a clean air filter can ensure the formation of a normal air-fuel mixture.
The recommended replacement interval is every 15,000 km. Timely replacement required air filter, because if it is clogged and you ignored it, then be prepared for the car to have a good appetite.
The flow rate is also affected by the use of air filter elements with heavy fabric pre-cleaners, because, as in the case of clogged filter, air resistance increases. Light type filter elements are recommended so that the resistance air flow was minimal.
#10 Driving style
If you drive a car with dynamic changes - it accelerates sharply and brakes sharply - of course, the fuel consumption of the car will increase significantly. It is also worth remembering about tuning and modified aerodynamic performance; it all costs money, including those that will have to be paid extra at the gas station.
Dynamic loads and machine overload contribute to excess fuel consumption
#11 Permanently on consumers of electricity
The operation of the air conditioner is especially affected - when the "air conditioner" is on, the car begins to consume more fuel. For example, on average, for every 100 km you need an additional 0.8 liters of fuel, so try to use the air conditioner only when necessary. It also has an effect on fuel consumption. Full time job headlights
Often, the behavior of the fuel indicator arrow begins to bother just when many energy consumers are involved, as well as auto congestion factors that novice drivers usually do not pay attention to. This includes a stove, air conditioning and various types of heaters (heated seats, windows, mirrors, pre-start, etc.).
#12 Car overload
When the car is loaded to the limit, for example, seven people sit down for 5 seats, and there is also some decent cargo in the trunk, then naturally more fuel is spent for movement vehicle. Every 100 kg of load means an increase of approximately 10%.
An empty roof rack raises consumption by 5%, and a loaded one by as much as 40%. The trailer at the back increases the sad indicator by all 60%.
#13 Driving with a cold engine
There is an opinion that you can save gasoline if you warm up the engine well before driving. It is only partly true. Yes indeed, warm engine spends less fuel. This is due to the fact that some of the thermal energy is spent on heating the housing and motor parts. However, this happens at an early stage. Therefore, a small part of gasoline is spent, roughly speaking, for other purposes. And when the engine is already warm, the thermal energy goes directly to the operation of the motor itself.
However this method fuel economy is questionable. The fact is that not much gasoline is spent on warming up the engine. And given that a certain amount of fuel is also needed for warming up, it turns out that saving by this method does not make sense.
What should be considered in this vein is that a cold engine emits much more harmful substances into the atmosphere. Some Western automakers write about this in the manuals for their cars. Therefore, it is better to warm up the car not in the garage, but in the fresh air.
Causes of excessive fuel consumption on diesel
Now consider the typical causes of excessive fuel consumption on diesel engines. Without touching on the general ones (for example, flat tires, carrying a heavy load, driving in a strong headwind), we will list only those that directly relate to the diesel engine.
- Clogged fuel and/or air filters . This is a common cause of excessive fuel consumption. Due to clogged filters, clogging of the fuel injectors also occurs. And this leads to a decrease in pressure in the injection pump.
- Mismatch engine oil . For a diesel engine, it is important to use oils that are recommended by the manufacturer.
- Reduced compression. It may wear out over time. piston group, and this automatically leads to increased fuel consumption by the engine.
- Partial failure of sensors. If for some reason the sensors provide incorrect information to the computer, then, accordingly, the device will generate incorrect commands.
- ECU problems. This problem is not common, but it can occur. Because of this, there may be program failures or other so-called "glitches".
As you can see, the faults are quite typical. Therefore, in order to prevent excessive fuel consumption, it is necessary to monitor the serviceability of the above nodes.
Engine types and typical causes of excessive fuel consumption
Here is a table for you, in which we systematize the causes of high fuel consumption, typical for various types engines.
| Causes of high fuel consumption, which relate to them | Engine types | ||
| Diesel | Carburetor | Injector | |
| Engine wear | |||
| Clutch wear | |||
| Incorrectly configured ignition | |||
| Tire wear | |||
| Weak tire pressure | |||
Despite the fact that for all cars produced from the assembly line, established fuel consumption rates are prescribed, in real life car owners are faced with a constant excess of prescribed indicators.
Fuel consumption is the most important characteristic to evaluate the performance of any vehicle. It is calculated using a special formula and depends on the distance that the car has covered. The standard is taken as 100 km of the distance traveled. For example, fuel consumption per 100 km for the VAZ-2104 is 8.5 liters. This figure is much less when driving on the highway.
However, due to a number of objective and subjective reasons, during the direct operation of the vehicle, it almost never coincides with the numbers indicated in the passport.
High fuel consumption is due to the following technical malfunctions:
- bad ignition;
- inappropriate temperature;
- gaps in ;
- failure piston-cylinder group;
- violations in the clutch system;
- wear of the crank device;
- deterioration of the gas distribution system;
- lack of wheel alignment adjustment;
- insufficient tire pressure;
- thermostat malfunctions;
- non-compliance with the periodic replacement of the air filter;
- mud deposits on the injector;
- destabilization of the sensors of the electronic functioning of the power unit.
Separately, one should consider problems that are associated with violations in the car's power supply system.
In addition to fuel consumption can lead to:
- the movement of the car with the windows open;
- vehicle overload;
- sharp manipulations while driving (braking, acceleration);
- violation of aerodynamic characteristics due to;
- continuous operation of additional functional devices (air conditioner, radio);
- headlights in working mode;
- the use of technical means that do not correspond to the parameters of a particular transmission and engine.
Violations in the power system
The car's power system is the interaction of devices such as a carburetor and a gasoline pump.
Carburetor- the main device in the vehicle that regulates the supply of fuel. Initially, the features of this process are adjusted and controlled by the manufacturer, but very often in the process of direct work they do not coincide with reality. Therefore, in most carburetors, you can reduce fuel consumption yourself. This work involves the adjustment of all dosing systems. All stages of this event must be performed in a certain sequence. Usually, they start with the depletion of the main metering system of the primary value chamber and only then correct the idle system. As a result, the operation of the carburetor is tested under heavy loads with the obligatory opening of the secondary chamber.
Functional malfunctions of the fuel pump can also lead to a sharp jump in fuel consumption. This is due to the incorrect dosage of the injected. In the event of such a problem, most likely, this mechanism will have to be replaced.
Technical malfunctions that increase fuel consumption
Quite often in cars there is a problem associated with ignition. In a situation where the ignition timing is shifted by at least one degree, fuel consumption immediately increases by at least 1%. Respectively, fuel consumption the higher, the larger the angle of displacement of this angle, and as a result, you become .
If the distance between the electrodes of the spark plugs exceeds the limit allowable rate- there are interruptions in the functioning of the spark plugs. Fuel consumption with their incorrect operation increases by as much as 4%.
Additional forces are also required to warm up an extremely cold coolant. It is produced only with the additional use of diesel or gasoline, the unforeseen loss of which will be 10%.
It is also very important to monitor the quality of the refueling fuel. It's not something you can skimp on. Otherwise, the components of the cylinder-piston group may be damaged, and this will necessarily lead to an increase in fuel consumption.
Video - the main causes of increased fuel consumption:
May decrease significantly as a result of wear piston rings and cylinders, which means a significant reduction in compression ratio. To compensate for the lack of power, the accelerator is used more and more often, and the fuel runs out earlier than expected.
Clutch - one of the main devices of the car. Malfunctions of its nodes lead to numerous slippages. Increasingly, squeezing the gas pedal, gasoline or diesel will inevitably spend much more noticeably.
There are many mechanisms in the gas distribution sector, the failure of which leads to a violation of the tightness of all cylinders. Thus, the end of the compression stroke and the beginning of the expansion stroke receive less required pressure. Engine power drops several times, and fuel consumption increases.
Inspection and control of wheel alignment should be carried out in without fail after the vehicle has traveled a certain distance. It is known that many problems with the vehicle, in particular the loss of its controllability, are associated with incorrectly adjusted wheel alignment angles.
Insufficient pressure in at least one tire increases fuel consumption by 3%. It is time to pump up the wheels with a pump.
Fuel consumption also increases with a dirty air filter.. It has an interfering effect on the air that must enter the engine and ensure one hundred percent combustion of the fuel mixture.
Thermostat malfunctions slow down. This is especially noticeable in winter period. It is clear that the fuel literally “melts before our eyes”.
Video - how to reduce fuel consumption:
A dirty engine injector is definitely the most common cause high fuel consumption. Mixing occurs much more slowly as a result Bad quality spraying fuel and changing the shape of the spray torch. Coefficient useful action decreases significantly at this rate. Problems of this kind, first of all, are manifested in the "triple" of the power unit and difficult gear shifting. The motor is running for wear, which, of course, indicates the useless use of diesel or gasoline.
Additional factors affecting fuel consumption
Each car has a cargo limit. However, few take this into account. Significant overloads lead to uncontrolled fuel consumption. Even an empty roof rack results in a 5% loss of diesel or gasoline.
Not everyone understands why high fuel consumption is associated with open windows. The point is that at fast driving with windows open, implied aerodynamics are disrupted, resulting in fuel wastage.
Additional equipment in the form also leads to a deterioration in aerodynamic performance.
The innovative electronics present in most modern models work solely due to fuel. At least 15% of it is spent on these charms.
For each type of engine, certain types have been developed. They differ in their viscosity. Should only be used suitable options, otherwise consumption fuel fluid can rise up to 10%.
The consumption of any fuel is closely related to literally all vehicle systems. Without it, even the operation of the headlights will become impossible. And you can't do without them in the dark.
Rules for maintaining fuel consumption within normal limits
However, getting upset in advance is never worth it. By following certain rules, fuel consumption can be kept under control..
This requires:
- Setting the correct ignition timing. This procedure is carried out on
- Carrying out control of the size of the gap in the spark plugs.
- Timely replacement of parts in all vehicle systems.
- Systematic alignment.
- Tire pressure monitoring.
- Use only suitable fluids and .
From all that has been said, it follows that it is almost impossible to avoid exceeding fuel standards. Car owners can only minimize this expense by using all the information above.
