Which factor primarily influences the towing capacity of a performance vehicle?

The factor that primarily influences the towing capacity of a performance vehicle is torque. Torque refers to the rotational force produced by the engine and is crucial for moving heavy loads. In towing scenarios, higher torque allows a vehicle to efficiently start moving heavy trailers and maintain the necessary speed while towing uphill or against resistance. This is because torque directly affects how well a vehicle can overcome inertia and grip the road, facilitating better acceleration and sustained performance when towing.

While horsepower is also an important measure of a vehicle's power, it is more relevant to maximum speed and performance at higher RPMs. Weight distribution can impact handling and stability when towing but does not directly dictate the vehicle’s ability to pull weight. Fuel type has no significant effect on towing capacity, as it largely influences efficiency and engine performance but not the fundamental mechanics involved in towing. Hence, torque is the key factor that determines a vehicle's towing capabilities.