by all means lower it if you wish to? and yes lowering it will affect the height of the tow ball dependant on low you go? as for tyre wear? well I went stupidly low! and never really suffered from it much, did it effect the ride quality? well yes it did, it was a hell of a lot better of a drive on fast smooth roads but on single track country roads you had to take it easy and mind the big pot holes! but as I said I went stupidly low :D slammed into the weeds on coil overs front and rear :D hence the LOW&LOUD VR6 tag I used to go under :D used to go under, ;) i dont remember that 1,lost count of the aliases you had.