Not sure what you find confusing about the drift recover. I'll try to make it more clear. The drift recover value is how quickly the direction the car is moving "catches up" to the angle the car is facing. What this means is, when the car is driving straight and turns to the right, it rotates its angle more quickly than the move direction changes. The default value for steer speed or the speed the car angle changes is, 225 degrees per second. The default drift recovery is 185 degrees per second. So, the default car object drifts and it takes almost a forth of a second for the car movement to match the angle of the car. To give the car a more noticable drift, you just need to set the drift recover value lower. A lower value makes the move dirction "catch up" slower so the drift lasts longer.
Try this, create a brand new car object with all the default values. Then, change the drift recover value to 50 and test it out by driving in a circle. You should see a rather drastic drift.