I've been experimenting with wheelcolliders and I'm having a bit of a hard time understanding the settings for friction. I assume that Extremum is synonymous with "Static" and "Asymptote" with Dynamic. So the Extremum slip point <Static Friction> is where an object will start to slip or "Break Free". Like pushing a desk, you have to push hard to get it started. The Asymptote slip value <Dynamic Friction> is the resistance to movement once an object has started moving. The desk, once moving, takes less effort to keep moving. Next is the "Slip" and "Value" items. I've got a suspicion what they are which I'll explain and I'm hoping someone can confirm or correct me. "Slip" appears to be the amount of slipping that can occur before reaching the break point where dynamic friction takes over. So even though the object hasn't "broken free" it still slips. "Value" appears to be the amount of force required to "break free" for Static Friction and the amount required to "level out", or stop dropping, for dynamic friction. So an approximate slip amount before breaking free would be something like Force / ExtremumValue * ExtremumSlip. In reality the slip amount is on a curve and this formula is plain proportional. At this point I haven't a hunch what Stiffness means. I took physics a few times and learned about coefficients of friction but no "stiffness" was ever involved. So am I right, wrong, close, waaay cold, or what? Thanks! Edit: I just had a thought. Is stiffness the "curviness" of the static curve? The higher the stiffness the sharper the curve is around the slip/value points?