Many drivers notice a peculiar phenomenon - after leaving city traffic and a few minutes of a more dynamic pace, the car seems to start breathing easier. The responsiveness when pressing the gas pedal improves, and the operation of the power unit becomes significantly smoother. There is nothing mysterious in this phenomenon, since it is a natural physico-chemical process in which the accumulated soot simply burns out under the influence of temperature.
The monotonous operating mode is one of the biggest enemies of the modern internal combustion engine. When the engine operates mainly in the low rev range, the combustion process does not proceed with maximum efficiency. The result of this is inevitable - a dense layer of undecomposed combustion products gradually forms on the valves, piston rings and in the combustion chambers. Over time, these deposits worsen heat transfer, shrink the combustion chamber and lead to loss of compression.
On the other hand, prolonged driving at the limit of critical capabilities is not at all a solution. Constantly reaching the red zone on the tachometer causes excessive mechanical wear, increases thermal load and accelerates thermal degradation of the engine oil. The optimal approach requires a reasonable balance - periodic short-term load, without prolonged overheating of the components.
The difference between urban rhythm and driving on country roads is enormous. Frequent stops, idling at traffic lights and short distances do not allow lubricants and coolant to reach their operating temperature quickly. The problem is exacerbated in cars equipped with automatic transmissions, whose software is set to shift up early to save fuel.
Certain operating conditions are required to start the self-cleaning process. During a country trip, it is advisable to maintain about four thousand revolutions per minute for a few minutes every hundred kilometers traveled. In vehicles with automatic transmission, this is easily achieved by switching to sports mode or manually selecting a lower gear.
In this specific mode, the temperature in the combustion chambers and exhaust system rises enough to break down freshly accumulated soot. At the same time, hot engine oil circulates at higher pressure and effectively washes away the softened deposits, directing them to the oil filter. An additional positive effect of this procedure is the complete heating of the catalytic converter, which activates its regenerating properties and extends its life.