What primarily contributes to rolling resistance in vehicles?

Rolling resistance in vehicles primarily results from tire flexing and surface penetration. As a vehicle moves, its tires undergo continuous flexing due to the weight of the vehicle and the load carried. This flexing causes deformation in the tire structure and the surface in contact with the road, especially when climbing over small imperfections or penetrations in the surface.

Each time the tire rolls, it compresses and then re-establishes its shape, consuming energy in the process. The material of the tire, as well as its construction, plays a significant role in the extent of this energy loss. Softer tires often exhibit more flexing, which can lead to higher rolling resistance compared to harder compounds.

While other factors like air pressure in tires, road surface texture, and vehicle speed do impact overall vehicle efficiency and performance, they are secondary contributors to rolling resistance. For instance, lower tire pressure can increase rolling resistance due to more flexing, but the fundamental source remains the flexing of the tire itself as it interacts with the road surface. Therefore, understanding tire flexing and surface penetration is crucial for evaluating energy losses due to rolling resistance in vehicles.