Wrong calculation of rolling resistance

[LBodnar]

I *think* those coefficients are set to zero like that because I was seeing tire forces generated without any slip, so the car would slowly start rolling on its own. That was a long time ago, though.

They should be treated like any other friction force:

1) Fx only appear when the tyre is rolling
2) if tyre is stationary it only starts rolling when applied driving torque exceeds Fx(0) * Re

Stationary and low speed tyre physics is not directly covered by Fx Fy Mz Pacejka formulas because the thread width cannot be considered zero anymore. There are local contact patch stresses that need some running length to dissipate and this translates into non-zero time at low speeds. E.g. heavy steering in a stationary vehicle creates a twist in the contact patch and generates counteracting Mz. When you start rolling slowly it will exponentially dissipate over a few tyre turns. I will come back to this later though.