Ontario Bus Driver Knowledge Practice Test

If you have exhaust or engine brake retarders fitted to your bus, you should be aware that...?

1. They may cause the vehicle to slide

2. They reduce fuel efficiency

3. They increase the risk of engine failure

4. They increase engine noise

The correct answer is: They increase engine noise

Having exhaust or engine brake retarders fitted to your bus can be beneficial but it's important to be aware that they can also cause an increase in engine noise. These devices work by creating back pressure in the exhaust system and can make a loud rumbling noise when used, which may be startling for other drivers on the road. This is why it is important to use these brake systems carefully and appropriately. The other options are incorrect because they either do not address the potential impact of these devices or are not relevant to their use. For example, while they may slightly decrease fuel efficiency, they are primarily used for safe braking and not for fuel savings. Similarly, they are not known to cause an increased risk of engine failure unless used improperly or if there is a malfunction with the device.