Why is the fuel consumption is always greater than the declared?

Continuing the theme of simple questions will be Week 2 photos in total.
When choosing a car low fuel consumption can be an important argument in favor of this or that model. But it has long been accustomed to the fact that the real rate is always greater than the declared automaker. So many drivers are asking: who and why they are cheating?





It turns out, the circuit measuring the fuel consumption of the new car is very cleverly organized and has little to do with the conditions of use of the machine the average driver. In Europe, for example, to estimate the fuel consumption of cars total weight up to 3500 kg there is a so-called "The new European cycle» NEDC. The duration of measurement is 1180 seconds (a little more than 20 minutes) and includes simulation drums urban driving at speeds up to 50 km / h and traffic on suburban routes at speeds up to 120 km / h. One test, for example, is the acceleration to 50 km / h in 26 seconds (imagine how long!). Total car passes all the tests for approximately 11,023 meters at an average speed of 33, 6 km / h.

Specialist Mazda's Andrei Glazkov claims that some manufacturers in the process of measurement may be slightly "podhimichit": "to resort to certain tricks - for example, the seams are sealed with tape body panels, thereby improving the aerodynamics. In theory, when a large motor with a good "appetite" so it is possible to reduce consumption by about half a liter. Large, world-known companies as, of course, do not. But the measure still held in ideal conditions. For example, tire pressure exhibited a maximum, it reduces rolling resistance and with it the flow ».

However, as we said a specialist company Porsche Russland Neupokoev Maxim, the main caveat is not the point. "The cycle NEDC - is riding in a certain ideal pace, bears little resemblance to the way people travel around us every day. We often accelerate or reset the gas - metering on the driver goes a long one, unusually low for our concept of speed and accelerates very slowly. But it is also important and that's what moment. During the measurement off all the "support" of the system - lights, heated seats, music, air conditioning ... But "powerhouse" for them is the engine - and to ensure the air conditioner can spend up to 4% of the engine power. It is not surprising that the claimed fuel consumption is always lower than the real, "- said Maxim Neupokoev.

It is no secret that to the fuel consumption indicated in the passport of the car, sometimes you can feel free to add a couple of liters,

But in the car there is a special device, showing fuel consumption. If we received in perfect conditions to the automaker believe 100% not worth it, maybe this device will tell the truth? "Digital fuel gauge in a car, too, has an error, and at times" stretching the truth ". It gives only a general idea of ​​what the driver is doing right and what is not, "- explains Andrei Glazkov. Therefore, the most effective method to find out how many actually "eat" the car is an old antiquated way - to fill up a full tank, drive 100 km and again fill up a full tank. The number of filled the tank liters with the second gas station and will be a real amount of fuel that is "drunk" the engine for 100 kilometers.

It should also be borne in mind that in different parts of the world fuel consumption measurement methods are very different. Therefore, figures in the technical data of the same vehicle in the "fuel" is often different.



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