When driving a new truck with a manual transmission down a long, steep hill, you should do what?

When driving a new truck with a manual transmission down a long, steep hill, using a lower gear is the recommended approach. Shifting to a lower gear helps to control the speed of the vehicle and utilizes the engine's braking capability to reduce the need for the brakes. This technique, known as engine braking, is particularly important on steep descents where continuous braking can lead to brake overheating and potential failure. By engaging a lower gear, the engine works in tandem with the brakes, allowing for safe and effective speed control without over-relying on the brake system.

Using a higher gear would increase the risk of speeding down the hill, as the truck would not benefit from the added resistance that a lower gear provides. Driving in neutral is unsafe, as it disengages the engine from the wheels, reducing driver control and eliminating the ability to brake effectively with engine assistance. Switching to automatic mode is not applicable here since the vehicle is already equipped with a manual transmission, and doing so may not provide the necessary control associated with a manual descent. Thus, selecting a lower gear is the best practice for maintaining control and safety in this scenario.