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

The correct answer highlights that exhaust or engine brake retarders can indeed increase engine noise. These devices are designed to assist in slowing down the vehicle by creating resistance in the engine, which contributes to a more efficient braking process. However, one of the trade-offs associated with their effectiveness is the added noise produced during operation. This noise is often considered a byproduct of how these systems function, and it can be particularly noticeable when the retarder is engaged.

It's important to be aware of the noise level as it can affect both the comfort of passengers and the overall noise environment in the surrounding area. Familiarity with this aspect not only helps in managing expectations but also aligns with regulations regarding noise levels in certain areas, especially in urban settings. Understanding this characteristic can ultimately contribute to safer and more responsible driving practices.