Among the following, which is NOT a factor in calculating total braking distance?

In calculating total braking distance, several factors are considered to determine how far a vehicle will travel from the moment the driver decides to brake until the vehicle comes to a complete stop. The correct answer highlights a factor that is not relevant to this calculation.

Speed of the vehicle is a critical determinant of braking distance, as faster speeds result in longer stopping distances due to increased momentum. Reaction distance is also included in the total braking distance calculation because it represents the distance the vehicle travels during the driver's reaction time before the brakes are applied. Braking distance refers specifically to the distance covered while the brakes are actively engaged until the vehicle stops.

In contrast, engine temperature does not directly affect the calculations of total braking distance. While it can indirectly influence vehicle performance under extreme conditions (like affecting brake performance), it is not a standard factor included in the basic calculations for total braking distance. Thus, it is the correct choice for what is NOT a factor in that specific calculation.