Continuing on the race car simulator series. Last week, the “effective tire friction” calculation was implemented, which modeled the grip at the point of contact between the tire and the road surface. This intentionally did not take into account the vertical load (or any other forces), since the purpose was limited to calculating the “effective” friction coefficient based on the material conditions. The next step was implemented yesterday, which calculates the effective force the tire will apply on the wheel axle, in reaction to the torque applied by the engine on the wheel axle. That reaction force will cause the car to move forward. It also factors in the existing inertial force (i.e. if the car is already moving) in order to model sideways slip (e.g. for drifting).