Specific fuel consumption of your car

As you know, the cost of gasoline is at least 30% of all costs for the operation of the car. Over-consumption 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 economy.

What it is? This characteristic indicates a set of operational characteristics that determine the fuel consumption of this particular car in different road conditions and operating modes. Depends on this indicator of the features of the design of the car, more precisely, the combination of the efficiency of the engine and transmission. Also, the fuel efficiency is influenced by the load-carrying capacity and the shape of the body, from the streamlining of which depends the additional fuel consumption for overcoming air resistance.

The quantitative characteristics of fuel economy are the road fuel consumption, that is, the number of liters of gasoline consumed per 100 kilometers on average (under normal operating conditions and typical road conditions), and the specific fuel consumption. Of course, this value is quite arbitrary, especially when moving in a megapolis, with its constant acceleration and braking.

The specific fuel consumption is its consumption per unit of work of the given car. This indicator is usually used when calculating the economic efficiency of transport (freight or passenger). It is calculated as the ratio of the average fuel consumption in terms of 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 determined by standard tests on the engine bench. The engine of the machine is forced to work with a certain load and a constant number of revolutions (adjusting the throttle position). Having deduced the engine on the set working point, fix a twisting moment on a shaft and define hour expense of fuel. Consequently, the smaller the obtained index, the higher the effective coefficient of action.

Compliance with the fuel consumption parameters set by the manufacturer depends on the adjustment and timely repair of the engine and on the operating conditions.

What can an ordinary driver do to improve the economy of his car?

Which driving style is the most optimal? Previously, when operating cars with carburettors at a load of about 80%, an economizer was activated and an additional injection of fuel was carried out, which led to an excess consumption of gasoline. Optimal in terms of efficiency in this case was the mode on the threshold of its inclusion, i.e. with a load on the engine of about 75%.

In the later released carburettors, the economy was achieved with a more powerful load, close to the maximum. In machines with injection engines, the peak of economy is about 90% of the load. Rapid acceleration with the pedal squeezed out against the pedal, contrary to popular belief, increases fuel consumption quite insignificantly (no more than 3-5%). Of course, all data are given only for ideal conditions of operation on a flat road.

But do we often have to ride on flat country roads with a small traffic load? Much more often the car is operated in the conditions of city streets with their inevitable traffic jams and traffic lights. Driving in the regime of constant acceleration-braking increases the specific fuel consumption to a considerable extent.

As is known, the most optimal type is the motion with a speed of 2000 to 2500 rpm and a throttle, which is approximately 20% open. Such a regime with intensive acceleration and braking is almost impossible to achieve, the engine's operation turns into uselessly combusted thermal energy.

Therefore, the only right advice to drivers in this case - if possible, to achieve a uniform, as smooth as possible ride (slow to move and brake). The expression "quieter ride" in this sense is more relevant than ever.