How does 3D Predictive Cruise Control (PPC / topography-based cruise control) enhance both passenger comfort and fuel efficiency on undulating highway routes?

1. It disables the engine cooling fan and cuts saloon air conditioning on every incline
2. It uses GPS and 3D topographic terrain map data to anticipate crests and dips, accelerating gently before hills and utilizing EcoRoll/coasting over crests to avoid harsh gear changes
3. It forces the vehicle to travel at the absolute maximum speed limit regardless of traffic conditions
4. It engages the mechanical retarder continuously on flat highway sections