High fuel consumption

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 the increased fuel consumption can be divided into two groups. In the first, the fault lies with the vehicle - the reason lies in any mechanical malfunctions. 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.
• Heating system operation... This applies not only to the operation of the "stove", but also to heated seats, glasses and mirrors (in cars where these options are provided). The logic here is similar to the situation described above.
• Sharp accelerations. If you like to pull away hard at traffic lights or other places, then be prepared for the fact that your car will consume more fuel than usual. This is because any transient (in this case, driving the car) is associated with increased energy consumption. And the sharper it is, the more energy is needed. Therefore, try to move smoothly. So you will not only save fuel, but also save tires, clutch and powertrain components.
• The operation of the internal combustion engine 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 internal combustion engine as a whole.
• Use of poor quality fuel. Try to refuel at proven gas stations and fill the tank with the brand of fuel recommended by the automaker. After all, bad fuel burns worse, provides insufficient energy and requires additional costs.

there are also a number of objective reasons why the 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

First, let's deal with the technical problems that contribute to an increase in gas mileage. Let's find out the most common causes associated with DVSm and other elements, due to which the consumption increases.

reasons for fuel consumption

1 ICE wear

Usually occurs due to the high mileage of the car or its incorrect operation. Some points related to the operation of the internal combustion engine:

• coolant (coolant) temperature is lower than calculated;
• wear of the cylinder-piston group;
• wear of the crank mechanism;
• wear of the gas distribution mechanism and unregulated valve clearances.

2 Clutch wear

Worn clutch disc

When the driver needs to keep high speeds in order to start 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. In the process of starting off, the engine consumes more fuel 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 machine stands still. The more often the car moves off, the greater the overspending of fuel takes place.

In critical cases, a similar situation can occur even when driving in a constant mode. That is, when the clutch disc does not provide synchronous rotation of the internal combustion 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 incorrectly configured ignition

Ignition setting

Incorrectly set ignition is also the cause of increased fuel consumption. namely, if the internal combustion engine "troits", then gasoline from an idle cylinder is thrown directly into the exhaust system. This leads not only to excessive consumption of fuel, but also to increased wear of the catalyst.

If the ignition is simply set incorrectly, then a situation arises when the fuel does not burn out completely. That is, the spark appears before the fuel mixture appears in the cylinder in full, or after. Whatever it was, it leads to its incomplete combustion. And this automatically means that 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 configured ignition system can cause problems when starting an internal combustion engine.

4 Amount of shin

 

Car tire wear affects not only fuel consumption, but also handling. Keep track of tire tread depth.

If the tires are worn out enough or 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, you need to replace the tires, and check the tire pressure regularly.

Low-profile tires with a wide tread create increased resistance and, accordingly, increased fuel consumption.

5 breakdowns of the brake system

They are different, consider those that lead to incomplete unclenching of the calipers when the so-called “wedging” occurs. If the caliper is not fully unclenched, then over time, not only the brake pads, but also the discs become unusable. Due to excessive friction and resistance, fuel consumption naturally increases.

6 Failed spark plugs

 

It is necessary to monitor the condition of the spark plugs.

Candles with an expired period put an additional load on the internal combustion engine. This leads not only to the fact that the internal combustion engine does not work correctly and there is a large fuel consumption, but also to a general deterioration in performance. in order to avoid, you need to check the candles.

Such a check 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. Do not forget about the resource

7 Clogged injectors or carburetor

 

fuel supply to the ICE cylinders and consumption depends on the condition of the fuel equipment.

Clogged injectors are one of the most common causes of excessive fuel consumption. They clog due to natural causes. These are the use of low-quality gasoline, the untimely replacement of the fuel filter, the ingress of dirt into the engine compartment, and so on.

With clogged nozzles, a violation of the shape of the fuel spray jet in the combustion chamber appears. Because of this, the formation of the fuel mixture is disrupted. That is, more gasoline is used for this process than is needed under normal conditions.

In some cases, due to clogging of the injectors, the internal combustion engine may begin to “troit”. This is expressed in a decrease in the dynamic characteristics of the car. it is also possible for the internal combustion engine to work at high speeds for a long time, even in idle mode. This in itself leads to an increase in fuel consumption.

Similar reasoning is valid for cars with a carburetor ICE. When the carburetor is clogged, the same situation appears with excessive consumption of gasoline and a drop in dynamic performance.

Therefore, always monitor the condition of the fuel system, namely, the injectors on the injection engine and the carburetor on the carburetor. Their clogging is a direct cause of excessive fuel consumption.

Low-octane fuel also has a great effect on consumption (for a low price and poor quality, it comes down to quantity).

8 Breakdown of the lambda probe or DMRV

The failure of the oxygen sensor (lambda probe) can also lead to a serious 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 also valid in relation to the mass air flow sensor (DMRV). It is designed to regulate the level of air supply to the internal combustion engine cylinders. sensor failures are easy to identify. usually, at the same time, the internal combustion 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 may temporarily remedy the situation.

9 Clogged air filter

 

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 of the air filter is required, 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, since, as with a clogged filter, air resistance increases. Lightweight filter elements are recommended to minimize airflow resistance.

10 Driving style

 

Dynamic loads and vehicle overload contribute to excessive fuel consumption

If you drive a car with dynamic changes - accelerate sharply and brake 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.

11 Permanently switched on electrical consumers

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 needed. also affects the fuel consumption of the constant operation of the headlights.

Often, the behavior of the fuel indicator arrow begins to bother just in the winter, when many energy consumers are involved, as well as car 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 Vehicle 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 to move the 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, a warm internal combustion engine consumes 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 internal combustion engine is already warmed up, the thermal energy goes precisely to the operation of the motor itself.

However, this method of saving fuel is questionable. The fact is that not much gasoline is spent on warming up the internal combustion engine. And given that a certain amount of fuel is also needed for warming up, it turns out that saving by this method is not worth it.

What should be considered in this vein is that an unheated internal combustion 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 internal combustion engines. Without touching on the general ones (for example, flat tires, transporting a heavy load, driving in a strong headwind), we list only those that specifically relate to a diesel engine.

1. Clogged fuel and/or air filters. This is a common cause of excessive fuel consumption. As a result of clogging of the filters, clogging of the fuel injectors also occurs. And this leads to a decrease in pressure in the injection pump.
2. Engine oil mismatch. For a diesel engine, it is important to use oils that are recommended by the manufacturer.
3. Reduced compression. It can go astray with the wear of the piston group, and this automatically leads to increased fuel consumption of the internal combustion engine.
4. Partial failure of sensors. If for some reason the sensors provide incorrect information to the computer, then, accordingly, the device will generate incorrect commands.
5. 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, breakdowns are quite typical. Therefore, in order to prevent excessive fuel consumption, it is necessary to monitor the serviceability of the nodes listed above.

Types of internal combustion engines and typical causes of excessive fuel consumption

We will give you a table in which we systematize the reasons for the high fuel consumption characteristic of various types of internal combustion engines.

Causes of high fuel consumption, which relate to them	ICE types
	Diesel	Carburetor	Injector
ICE wear
Clutch wear
incorrectly configured ignition
Tire wear
Weak tire pressure
breakdown of the brake system
Defective spark plugs
Clogged nozzles
clogged carburetor
Breakage of the lambda probe or DMRV
Clogged air filter
Clogged fuel filter
Included energy consumers
Vehicle overload
Driving with an unheated internal combustion engine

Summing up

So, after analyzing all of the above, it is easy to draw a conclusion and at least approximately determine the reason why a particular car suddenly began to consume more fuel. sometimes this is a signal for a serious breakdown, and sometimes it’s just inattention to one’s own in their actions. Therefore, before panicking, it is worthwhile to carefully weigh the possible causes of influence.