Well, that's what I have been told by the so called 'experts' (dealer/Tirerack)
Another tidbit I learned during my last conversation with Tirerack:
If you have tires that offer a treadwear warranty thru the manufacturer, & you are running a staggered tire size setup - the treadwear warranty is VOID - even if the tires are worn evenly and you have proof of regular alignments