When driving in mountainous terrain, which of these does NOT affect your choice of gears?

When driving in mountainous terrain, the choice of gears is largely influenced by factors such as the grade of the hill, the weight of the vehicle, and the road conditions ahead. The grade of the hill determines the steepness of the incline or decline, which directly impacts how much power is needed from the engine and thereby affects the gear selection. Heavier vehicles require lower gears to manage the extra weight effectively, particularly when climbing steep grades or descending in order to avoid overpowering the brakes.

Road conditions ahead, such as whether the road is icy, wet, or has sharp turns, also play a critical role in selecting the appropriate gear. Safe driving practices dictate that the driver must adjust their speed and gear selection to accommodate these conditions for optimal control and safety.

In contrast, tire tread type does not significantly influence gear choice. While tire tread can affect traction and handling, it does not impact the mechanical aspects of gear selection in relation to terrain. Therefore, while important for safety and handling, tire tread type is not a determining factor in deciding which gear to use when driving in mountainous terrain.