Hi Benji. I'm pretty sure the axle naturally wants to go down as it is so pushing more air in with a lifted wheel won't cause it to touch the ground. I only noticed lifting wheels off road when the shocks reach their limit. Except in the case where the car is lifted on a jack using the diff or towards the centre of the axles, nut adding air here only lifts the body and not push the wheels down.
But I could be wrong... Let me think and ponder a little more...
Peter

