What performance metrics are evaluated in terms of fuel efficiency and distance traveled?

Fuel burn and range are critical performance metrics when evaluating fuel efficiency and distance traveled in aviation. Fuel burn refers to the amount of fuel consumed by an aircraft during flight, which directly impacts operational costs, environmental efficiency, and overall performance. A lower fuel burn indicates better fuel efficiency, meaning the aircraft can fly longer distances on less fuel, which is vital for airlines aiming to reduce expenses and emissions.

Range, on the other hand, represents the maximum distance an aircraft can cover on a specific amount of fuel. It is an essential metric as it determines the aircraft's capability to perform certain routes without the need for refueling. A longer range allows airlines to serve more destinations and operate more efficiently on longer flights.

The other options, while important in their own right, do not speak directly to the metrics of fuel efficiency and distance traveled. For example, engine maximum temperature is more related to operational safety and performance limits rather than fuel efficiency. Maintenance cycle length pertains to aircraft upkeep and operational readiness rather than fuel use or distance metrics. Lastly, passenger capacity is focused on the number of passengers the aircraft can transport, which does not consider how efficiently it burns fuel or the distances it can travel.