What is the most effective way of speeding up a bus?
Show the correct answer
Correct answer
B. By changing gears in such a way that the RPM of the engine is not lower than the starting value of the green area on the tachometer.
Explanation
In the photo a bus is standing at bay 8 of a bus station. You accelerate a bus most effectively by changing gear so that the engine speed does not fall below the start of the green zone on the rev counter - answer B.
The Road Traffic Act prohibits the driver from using a vehicle in a way that causes nuisance through excessive exhaust emissions or excessive noise. The green zone on the rev counter shows the range in which the engine has the highest torque with the lowest fuel consumption. You change gear so that after you select a higher gear, the revs stay in this zone - then the bus accelerates smoothly and the passengers do not feel jerks. Revving the engine to the maximum in every gear (answer A) wastes fuel and makes noise, and driving in the red zone (answer C) risks damaging the engine. In an empty bus you can also often skip a gear.
Legal basis: Art. 60 para. 2 point 2 of the Road Traffic Act (Prawo o ruchu drogowym)