On average, how much diesel fuel does an idling truck use every hour?

Answer: B — One gallon

An idling truck typically uses about one gallon of diesel fuel per hour. This figure is an important consideration for drivers and fleet managers, as it highlights the fuel inefficiency associated with idling. When a truck is left running while not in motion, it consumes fuel without providing any productive work or distance traveled. This not only increases operational costs but also contributes to increased emissions, which can be detrimental to the environment. Understanding this fuel consumption can encourage drivers to turn off their engines during long stops, further promoting fuel savings and environmental responsibility.