As you know, the cost of gasoline is at least 30% of the total cost of operating a car. Overexpenditure of fuel, the search for ways to avoid it or at least reduce it is a constant headache for both car designers and ordinary car owners. Therefore, among the most important consumer qualities of your car in one of the first places - its fuel efficiency.
What it is? This characteristic denotes a set of operational features that determine the fuel consumption of a particular car in different road conditions and operating modes. This indicator depends on the design features of the car, more precisely, on the totality of the efficiency of the engine and transmission. The fuel efficiency is also influenced by the load factor and the shape of the body, on the streamlining of which the additional fuel consumption to overcome air resistance depends.
The quantitative characteristics of fuel economy are line fuel consumption, i.e., the number of liters of gasoline consumed per 100 kilometers on average (under normal operating conditions and typical road conditions), and specific fuel consumption. Of course, this value is rather arbitrary, especially when driving in a megalopolis, with its constant acceleration and braking.
Specific fuel consumption is its consumption per unit of work of this vehicle. This indicator is usually used in calculating the economic efficiency of transportation (freight or passenger). It is calculated as the ratio of average fuel consumption in terms of a unit of engine power to the distance traveled (specific consumption per 1 km of track). Or the flow rate is determined per unit time (per hour or per second).
Specific fuel consumption is established by standard tests on a motor stand. The engine of the machine is forced to work with a certain load and a constant speed (by adjusting the position of the throttle). Having brought the engine to a given operating point, fix the torque on the shaft and determine the hourly fuel consumption. Therefore, the smaller the obtained indicator, the higher the effective coefficient of action.
Compliance with the fuel consumption parameters specified by the manufacturer depends on the adjustment and timely repair of the engine and on operating conditions.
What can an ordinary driver do to increase the efficiency of his car?
What is the best riding style? Previously, when operating cars with carburetors at an load of about 80%, the economizer was switched on and carried out additional fuel injection, which led to excessive gas mileage. The optimal economy in this case was the mode at the threshold of its inclusion, i.e., at an engine load of about 75%.
In later released carburetors, economy was achieved with a more powerful load, close to maximum. In cars with injection engines, the peak of efficiency falls on the load of about 90%. Quick acceleration with the pedal depressed all the way, contrary to popular belief, increases fuel consumption quite slightly (no more than 3-5%). Of course, all data is provided only for ideal conditions on a flat road.
But how often do we have to ride on flat suburban highways with low traffic load? More often, the car is operated in urban streets with their inevitable traffic jams and traffic lights. Riding in continuous acceleration-braking mode increases specific fuel consumption to a significant extent.
As you know, the most optimal is the type of movement with a speed of 2000 to 2500 rpm and a throttle open by about 20%. It is practically impossible to achieve such a regime with intensive acceleration and braking; the engine operation turns into uselessly combustible thermal energy.
Therefore, the only right advice for drivers in this case is to achieve a uniform, as smooth ride as possible (move slowly and brake). The expression "quieter ride" in this sense is more appropriate than ever.