Which factor is said to affect driveline characteristics?

The correct answer to the question about factors affecting driveline characteristics is that both wheel diameter and suspension height can indeed have an impact.

Wheel diameter plays a crucial role in determining the overall gearing and torque multiplication experienced in the driveline. Larger wheels can alter the vehicle's effective gear ratio, which can affect acceleration and engine performance. When wheels are larger, the vehicle may require more torque to accelerate, and this can influence how the power is transmitted from the engine through the drivetrain.

Similarly, suspension height affects the driveline dynamics as well. A vehicle with a raised suspension may experience changes in the angles at which the driveshafts operate, which can lead to increased wear on U-joints and potentially affect driveability. Height changes can also alter the handling characteristics and weight distribution of the vehicle, influencing its stability and traction.

When considering these factors together, it's clear that both wheel diameter and suspension height significantly affect the driveline characteristics of a vehicle. Understanding these aspects is vital for anyone involved in working with or modifying vehicles, particularly in the context of performance and handling.