Why does the car smoke so much? What is economical driving?

When your car burns too much, it could be due to both engine failure and driving style. We advise how to check it.

It is very difficult to achieve the fuel consumption figures declared by car manufacturers. The catalog data was obtained under laboratory conditions, which is almost impossible to reproduce in normal traffic. So when a car that should burn 8 liters of gasoline burns one or two liters more, most drivers are not surprised.

More on the topic: Catalog fuel consumption and reality - where do these differences come from

Start with yourself

Problems begin when the declared eight turns into 12-14 liters. Instead of going straight to the mechanic, consider your driving style. According to experts, the most common cause of increased fuel consumption is driving on an underheated engine.

“The problem mainly affects drivers whose car is only used for short trips. By the time the engine reaches its optimum temperature, it is turned off. Then it works all the time on the choke, which in most modern cars is automatic and cannot be turned off, explains Stanislav Plonka, an auto mechanic from Rzeszow.

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This problem most often occurs in winter, when warming up the engine is much more difficult. The easiest way to help the engine in such a situation is to cover part of the air intakes. This can be done both with ready-made casings available in stores, and with a piece of cardboard or plastic.      

Driving style is also important.

– By accelerating and braking frequently, we will use much more gas than if we were driving at a steady pace. We must not forget about engine braking. Most often, drivers forget about it, reaching a traffic light. Instead of rolling towards the traffic lights, they throw up the slack,” says Roman Baran, Polish mountain racing champion.

The driver must also choose the gear ratio wisely. We turn on the increased gear at 2500-3000 rpm. A higher load on the engine will certainly affect the result of combustion. This is easy to verify by observing the current fuel consumption on the on-board computer display.  

Turn on road thinking, you will save a lot of fuel

The appetite for fuel is increased by extra pounds and elements that increase air resistance. This, for example, is a roof box that you should not take with you if you do not need it at the moment. The same remark applies to roof racks and ski or bike racks. You should get rid of unnecessary items from the trunk, especially the tool kit.

– In addition to the main elements, i.e. screwdriver and wheel wrench, it makes no sense to carry other tools with you. Most modern cars are so crammed with electronics that without a computer with specialized software, the driver will not fix the defect on his own, says Stanislav Plonka.

It's a good idea to leave cosmetics and a car wash brush in the garage, which constantly live in many trunks.

injection, brakes, exhaust

Among the mechanical causes, problems with the fuel and injection systems should start. A very likely source of trouble is a faulty pump, injectors, or controller responsible for dosing and dispensing fuel. In this case, diagnosing the problem requires a visit to the mechanic, but some symptoms may hint at this.

- These are, for example, a change in the color of the exhaust gases, a sharp drop in power and engine flooding. In older cars equipped with a carburetor, the smell of spilled gasoline can be felt without even lifting the hood, says Stanislav Plonka.

How to reduce fuel consumption by 25-30 percent - a guide

Like a roof rack, inoperative brakes create additional drag. Stuck cams, broken pistons and cylinders can cause the brake to simply hold the wheel while moving. The easiest way to diagnose is to raise the car on the channel and spin the wheels. If everything is in order, it should become light and the wheel should have no problem completing a few revolutions.

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Another suspect is the exhaust system.

– A worn out catalytic converter or muffler is a natural obstruction to the exit of exhaust gases. And if the engine can't get rid of them, the choker burns more fuel than it should, explains Stanislav Benek, an experienced exhaust system repair mechanic.          

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A damaged lambda probe can also be the cause of improper combustion. It analyzes the oxygen content in the exhaust gases, so that the engine controller can determine the most optimal composition of the fuel-air mixture. Thus, the engine not only runs normally, but also receives as much fuel as it really needs.

Governorate Bartosz

photo by Bartosz Guberna