What type of engine oil should you use in diesel engines used in buses?
Show the correct answer
Correct answer
C. As specified by the bus manufacturer.
Explanation
In the photo you can see a yellow engine oil filler cap with an oil can symbol and the word "OIL". In the diesel engine of a bus you use the oil specified by the manufacturer - answer C.
The Road Traffic Act requires a vehicle to be maintained so that using it does not endanger safety and does not cause excessive emission of harmful substances. The manufacturer chooses the oil for the engine design: it states the viscosity, the quality class and the standards, which take into account loads, operating temperatures and the exhaust cleaning system. "Any" oil (answer A) may not protect the engine against wear or may block the particulate filter. Choosing oil according to the current engine temperature (answer B) makes no sense - the engine warms up while driving, and the oil must work across the whole temperature range. You will find the recommendations in the bus owner's manual.
Legal basis: Art. 66 para. 1 point 1 and 3 of the Road Traffic Act (Prawo o ruchu drogowym)