Elapsed Revolutions (Rear)
The Elapsed Revolutions (Rear) label reports the number of revolutions that the drive wheel of a two-wheel drive vehicle has turned at the current time point of the simulation. If the car is a four-wheel-drive design, it reports the number of revolutions that the rear drive wheel has turned.
If you are simulating a four-wheel drive vehicle, you may have noticed that the elapsed revolutions for the front and rear are often different. For more information about this effect, see Elapsed Revolutions (Front).