How are lubricating points lubricated on motor vehicles and trailers?

The correct answers highlight two main methods used for lubricating points on motor vehicles and trailers. Central lubricating systems distribute lubricant from a reservoir to various lubrication points automatically or semi-automatically, ensuring adequate lubrication across multiple components without requiring frequent manual intervention. This system is crucial for maintaining the vehicle's performance and longevity.

On the other hand, manual lubrication with a grease gun allows for targeted application of grease directly to specific lubrication points. This method is often employed in situations where central systems are not used or when certain components require additional attention.

The third option, which involves regularly checking engine oil levels, while important for engine maintenance, is not a lubrication method for specific lubrication points and thus does not belong to the correct answer set. Understanding these lubrication methods aligns with German traffic laws, which emphasize vehicle maintenance for safety and efficiency, ensuring vehicles operate reliably on the road. Adhering to proper lubrication practices helps prevent mechanical failures, which can lead to accidents or breakdowns, reinforcing the importance of the selected methods.