Decreasing wheel friction with velocity

I want to have my car wheels to have less sideways friction at higher speeds, how do i do this? this is the code i have so far... but it doesn't work.

var slip = 0.022 - (rigidbody.velocity.magnitude / 150);

BackRightWheel.WheelHit.sidewaysSlip = slip;

I'd change your code to:

var slip : float;

BackRightWheel.sidewaysFriction.stiffness = slip;

Also I'd clamp the slip value to make sure it never reaches 0 or some other minimum value.

To use math clamp you do this:

slip = Mathf.Clamp(slip,min,max)


slip = Mathf.Clamp(slip,0.001,0.022);

If you wanted a smooth curve instead of a linear line you can use this formula instead:

slip = 0.001 + 0.022/(rigidbody.velocity.magnitude+1)