1. For urban traffic, the so-called urban cycle is prescribed, consisting of 25 separate races. Among others, there are idling, acceleration, shifting, braking, various speeds: 10, 15, 32, 35, 50 km/h.
2. Then driving is carried out at a constant speed of 90 km / h.
3. Then follows the movement at a constant speed of 120 km / h.
Flow measurement and entry in the travel book
For current consumption observations, a travel book is best suited. Flow measurements are carried out as follows.
In the book, write down all the amount of fuel poured into the tank. Every 2000 km, after a full refueling, enter the exact number of kilometers traveled in the book.
Sum all amounts of fuel filled between two recorded speedometer readings (in km). Total fuel consumption divided by distance traveled in km (at least 1000 km), then multiply by 100. The resulting value gives fuel consumption in liters per 100 km of distance traveled.
Consumption in theory and practice
The following table compares normal flow data and established practical values (with standard gearbox).
Factors on which fuel consumption depends
Weather. Humidity and temperature affect combustion, especially for a diesel engine. Therefore, on clear winter days, a car warmed up in motion drives well. Air in cold weather and at high pressure has a greater density than in hot weather. A headwind slows down progress: a tailwind, on the other hand, helps save some fuel. Cold contributes to a better viscosity of lubricants, which enable all rotating parts to withstand higher resistance. Snow and sticky mud on the roads increase rolling resistance, which causes additional fuel consumption.
Type of roadway and condition of the road. Wheels roll on smooth concrete or asphalt more easily than on rough road surfaces such as gravel or country roads. In addition, on bad roads, you often have to drive at a lower speed and lower gear, which further increases fuel consumption.
Mountains. Not only the road uphill requires additional fuel consumption. In regions located at higher elevations, the air pressure is less, as a result, the diesel engine develops worse power. It is hardly possible to save fuel when driving uphill or downhill. In this case, the brakes are too heavily loaded, if you do not additionally brake with the help of the engine. But then it works unprofitably, in the area of high speeds.
Driving in stop-and-go mode, constant stalling and braking, long periods of idling - all this increases fuel consumption.
Consumption under normal conditions | city traffic | At 90 km/h | At 120 km/h | Average |
Engine 1.5 L | 6,8 | 5,3 | 7,8 | 6,6 |
1.6L engine and 4-speed gearbox | 6,8 | 5,3 | 8,0 | 6,7 |
1.6L engine and 4+E gearbox | 6,8 | 4,8 | 7,0 | 6,2 |
Engine 1.6 l gearbox 3+E | 6,0 | 4,5 | 6,6 | 5,7 |
Turbodiesel engine and 4+E gearbox | 6,6 | 4,5 | 6,7 | 5,9 |
Consumption in practice | city traffic | rural street | Motorway | Average |
Engine 1.5 l and 1.6 l | 6,7 | 5,7 | 8,2 | 6,8 |
Turbo diesel engine | 6,5 | 5,2 | 8,9 | 6,9 |
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