If you admit only fast driving, press the accelerator pedal to failure in any case, and brake only at the last moment, then high gas mileage is a common thing for you. There is only one advice in this case - try to drive less aggressively.
The fuel supply system has nothing to do with it. It does not matter whether the engine is equipped with an injector or a carburetor - a high flow rate is ensured. Try to learn how to drive smoothly: this will not only help reduce fuel consumption, but also extend the life of the chassis, transmission and engine.
PROBLEMS IN ELECTRONICS
In modern cars, the engine operating mode is controlled by a computer. An electronic control unit (ECU) regulates the fuel delivery to optimize the air-fuel ratio based on the load. The reason that the engine with an injector has a high flow rate may be incorrect operation of the sensors, with the help of which the ECU analyzes the operation of the units.
THROTTLE BODY SENSOR
If the sensors underestimate the actual volume of incoming air, the computer prepares a leaner mixture than necessary. As a result of a malfunction, the engine cannot develop the required power, the driver often presses on the gas pedal, provoking overruns.
The throttle valve can be cleaned with Fuel System Cleaner for a petrol engine.
High fuel consumption in a car is possible if the coolant temperature sensor is damaged! The on-board computer controls engine operation based on inaccurate information. If the temperature in the engine is above normal, the fuel that has entered the cylinder quickly evaporates, and the air contains less oxygen, therefore, the combustion of the air-fuel mixture will not occur correctly.
Engine power drops. The on-board computer, misled by the temperature sensor, gives the command to increase the injection, but there is still not enough air to burn gasoline, so some of the fuel is thrown into the pipe. This leads to increased consumption.
These devices measure the amount of oxygen in the exhaust. If the oxygen sensor shows that there is a lot of O2 in the exhaust gases, then the air-fuel mixture is poor - oxygen does not completely burn out. Correcting the situation, the computer increases the amount of fuel in the injection.
In case of erroneously high readings of the lambda probe, the ECU considers that it is necessary to inject more gasoline even at idle, although in fact the engine is working optimally. That is why a large gas mileage is possible in the event of a malfunction of such an insignificant part as an oxygen sensor.
It is very difficult to find a malfunction in the electronics on your own - even the technicians may take some time to determine which sensor has failed. If the reason lies in the sensors, carry out computer diagnostics of the car in a reliable car service.
Fuel system pressure deviation
If there is not enough pressure in the fuel system, the spray quality and the amount of fuel will decrease, and the engine power will decrease. Even if the on-board computer gives the command for the maximum pulse duration, insufficient fuel is injected.
Often the increased consumption of Nissan, Toyota and other brands with automatic transmissions is due precisely to the low fuel pressure. The automatic machine goes longer in lower gears, when the engine efficiency is lower, therefore, the fuel consumption is higher.
If there is a suspicion that the pressure in the fuel system is lower than permissible, the fuel lines should be checked at the time of the leak. If everything is in order with them, check the pre-filter and fine filter: curled filter elements lead to a drop in pressure. The next in line is a gas pump. A worn-out appliance will not be able to pump enough fuel.
If the problems have begun recently, you can try to fix the situation without large financial costs. Instead of costly repairs and parts replacement, use a fuel system flush.
Increased consumption at the injector
Drivers do not often complain about the high fuel consumption of Toyota, Nissan or other cars of reputable Japanese brands. Quite often, excessive fuel consumption is associated with contamination of the injection nozzles.
Due to low-quality gasoline, the nozzles are "overgrown" with carbon deposits. As a result, the shape of the torch is distorted, spraying deviates from the optimal values. Part of the air-fuel mixture burns not in the cylinders, but in the exhaust manifold, without performing any useful work. The efficiency of the engine drops, which is why high gas mileage with dirty nozzles is inevitable.
To prevent contamination of injectors, in order to avoid an increase in fuel consumption by an injector for Toyota, Nissan or another car, you can use the compositions mentioned above. These products wash away varnish deposits from the spray nozzles, restoring the geometry of the injection spray. As a result:
Clogged air filter
For absolutely any engine, of any size: both 2.2 and 1.6, high fuel consumption is possible if the air filter is clogged. The problem is not only that less oxygen enters the combustion chamber. Much more on the operation of the motor is influenced by the fact that the flow meters of the incoming air give the computer incorrect information.
As a result of an error, the ECU incorrectly calculates the motor load. This means that the mixture is being prepared based on incorrect data. On engines and 1.6 and 2.2, high fuel consumption in this case is provided. However, this does not depend on the volume of the engine, but on a 5 liter monster the difference is more noticeable.
Engine wear is one of the reasons for high fuel consumption
As a rule, high gasoline consumption due to engine wear is observed on vehicles with high mileage. The reason is that the piston rings and cylinder walls wear out first, the gaps between them increase, and gases from the combustion chamber break through into the crankcase. This leads to a drop in compression, loss of working gas and, as a result, a decrease in engine efficiency.
Coking of the piston rings leads to the same consequences. The sealing elements "lie down", the tightness of the conjugation in the piston-cylinder pair decreases, which leads to the breakthrough of combustion products. That is, gasoline burns out without doing any useful work. The efficiency of the motor decreases and the fuel consumption increases.