You are driving a motor vehicle with a manual gearbox on a level carriageway. How should you change gears so as to drive in a particularly environmentally conscious and economical way?

The selected combination of choices is correct because driving in an environmentally conscious and economical way involves two main strategies: changing gears early and changing down late.

1. Changing up gears as early as possible helps the engine operate at lower RPMs, which reduces fuel consumption and emissions. This method optimizes engine efficiency and encourages smoother driving.

2. Changing down gears as late as possible means keeping the vehicle in higher gears longer before shifting down. This practice allows the vehicle to maintain momentum and engine efficiency, which minimizes fuel wastage.

These strategies align with promoting fuel efficiency and reducing environmental impact, as highlighted in various German traffic regulations aimed at encouraging eco-friendly driving practices. Following these methods not only adheres to rules but also contributes positively to the environment by lowering carbon footprints.