As previously stated, it is called tramlining. Described here..
http://www.tirerack.com/tires/tirete....jsp?techid=47
Changing from RunFlat tyres to NON RunFlat tyres on my X3 xDrive 30d MSport with 19" Staggered setup on summer tyres made a very noticeable difference with no tramlining.
I still have RunFlat tyres on my 18" winter wheels and tramlining is very evident.