Quote:
It's inaccurate to assume that as the section width or tread width increases that the contact patch area also increases. Nor does it remain constant as [Vertical Force] / [Constant Inflation Pressure] suggests. Conceivably, it could decrease depending on the relative vertical stiffnesses. But what will change is the shape of the contact patch, becoming shorter in the longitudinal direction as it is made wider (assuming a constant load), and this may be partly responsible for more uniform unit loading over the area of the contact patch. All else equal, integrating a more uniform unit load and associated grip coefficient function over the entire contact patch should give more total lateral grip. The wider tire probably also has higher vertical and lateral spring rates, meaning less camber loss and lateral distortion in actual driving respectively.
BTW, the drag strip crowd tends to run tires that give relatively longer contact patches . . .
From here: