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The driving cycle is a virtual route for which all acceleration and deceleration are strictly prescribed, their intensity and duration, maximum and minimum speed. In addition, for a machine with a manual transmission, even a transmission is stipulated, which must be included at every moment in time. In fact, this is an imitation of traffic in cities and on highways characteristic of a particular locality.
For correctness, measurements are carried out in laboratories, on running drums. Operators set the necessary conditions and monitor the work of the test driver. Sometimes a person sitting behind the wheel is replaced by automation
For correctness, measurements are carried out in laboratories, on running drums. Operators set the necessary conditions and monitor the work of the test driver. Sometimes a person sitting behind the wheel is replaced by automation. For correctness, measurements are carried out in laboratories, on running drums. Operators set the necessary conditions and monitor the work of the test driver. Sometimes a person sitting behind the wheel is replaced by automation.
There are three main methods: European, American and Japanese. In order to exclude the influence of weather conditions, terrain and the quality of the coating on the final results, tests are carried out in the laboratory, on running drums. That is why the data obtained in greenhouse conditions often differ from the real ones. However, the only way to compare the performance of different models as correctly as possible. In addition, the output receives a certain amount of particles and gases that the engine threw during this time. If the car goes on the road, collecting its exhaust in a special bag is a difficult task.
So, knowing the mass of emissions, you can calculate the amount of fuel that the car has consumed.
On running drums they simulate ideal and at the same time very real road conditions: temperature 20–22 ºС, atmospheric pressure close to normal, additional blowing of the front of the car for optimal engine cooling
On running drums they simulate ideal and at the same time very real road conditions: temperature 20–22 ºС, atmospheric pressure close to normal, additional blowing of the front of the car for optimal engine cooling. On running drums they simulate ideal and at the same time very real road conditions: temperature 20–22 ºС, atmospheric pressure close to normal, additional blowing of the front of the car for optimal engine cooling.
AUSTRALIA
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This technique has been developed in Australia. The local cycle is called CUEDC (Composite Urban Emissions Drive Cycle). The half-hour (1797 s) program for gasoline cars includes four types of traffic - from city traffic jams to the highway. The average speed on the route is 38.95 km / h, higher only in North America.
JAPAN
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The Japanese JC08 driving cycle has been operating since last October. For 1204 s, the car “drives” 8.17 km with an average speed of only 24.4 km / h. The reason for such a modest indicator was significant downtime that mimics the expectation of traffic lights - this is where the advantage of hybrids or models with a start-stop system is most noticeable. By the way, excluding these stops, we get already comparable to European 34.8 km / h. The proximity of these techniques is understandable: both are affected by crowding in megacities. Therefore, the indicators for the mixed cycle for tests in Japan and in the Old World are close enough that the average consumer can directly compare them. Just keep in mind that in the Land of the Rising Sun, it is not fuel consumption that is recorded, but the power reserve: how many kilometers the car will travel per liter. However, even a student will be able to recalculate this value in liters per 100 km.
USA
The North American driving cycle, or, as it is often called, the FTP-75 federal test procedure, consists of three phases (Fig. A).
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The initial and final parts, each lasting 505 s, are identical. Between them, the car “moves” for 860 s, then they shut off the engine for 10 minutes. At an average speed of 34.1 km / h, the test car “passes” 17.8 km. Compared to the European methodology, the FTP-75 looks stiffer: already in the fourth minute, the speed reaches 90 km / h (simulating traffic on nearby suburban roads), and the number of starts in 31.2 minutes reaches twenty-two. Moreover, two corrections are applied to the main driving cycle, allowing to bring indicators closer to real ones. These ten-minute tests show how driving at high speeds with sharp accelerations (US06 cycle), as well as the air conditioning (SC03 cycle), affects fuel consumption.
In Americans, appetite for the track is measured in a separate test (HWFET, HighWay Fuel Economy Test). This test (Fig. B):
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It lasts almost twice as long as the similar European suburban phase (765 s versus 400) and assumes a quarter higher average speed (77.7 km / h versus 62.6). The transatlantic proportions used to calculate fuel consumption in the combined cycle are also significantly different: Americans wind up 55% of their mileage around the city and surrounding areas, and only 45% - along highways.
Volkswagen experts tested a car with a 1.4-liter gasoline engine using different methods and found that in the certification documents for the USA fuel consumption is 10-16% lower than European data. Only American buyers will not see these numbers. Manufacturers use increasing factors to more or less equalize indicators and protect themselves from possible lawsuits. The amendments, by the way, sometimes exceed 30%.
