[basjoos]

Originally Posted by MetroMPG

Yup, it seems counterintuitive. But from the mouth of the Michelin Man himself ...

Source: http://automotive.ing.unibs.it/~gado...istance_UK.pdf

While it is true that a hard plastic wheel rolls easier than a wheel with a soft rubber tire, you are looking at different materials, one of which has a miniscule contact patch and the other which has a much larger contact patch.

The drop in a tire's rolling resistance with increasing temp is likely a result of warm rubber flexing easier than cold stiff rubber. The rubber has to flex to accommodate the flat contact patch and the easier it flexes, the lower the rolling resistance. Also as the tire heats up, its internal psi also increases, reducing the size of the contact patch.