Step 3 » GENERAL learning environment Category D (D, D1, Tb, Tv)

For answer  A 

The oil in the engine ensures optimal lubrication at a certain temperature. If the engine does not reach this temperature, the viscosity of the oil is higher than it should be and the friction resistance is higher. Therefore, driving with the cooling system thermostat defective, the coolant having a temperature below 60 degrees Celsius, leads to an increase in fuel consumption.

For answer  B 

Black-coloured smoke emitted through the exhaust indicates excessive fuel consumption. This can be the consequence of injector failure (clogging of the nozzle holes), the injector needle jamming, the injector needle not sealing, etc.

For answer  C 

Running with interruptions can be caused by faulty injector operation or by a mixture too rich in fuel, thus burning more fuel compared to normal operation. Therefore, the engine running with interruptions leads to an increase in fuel consumption.

The situations in all three answers lead to increased fuel consumption.

The correct answer is: A, B and C

Recommendations:

Mechanics course (knowledge of the main elements) --> Mechanics course