Besides tread wear, tires wear out from the constant flexing of the sidewalls twice per wheel rotation. That wear is not taking place when the car sits. You also have to consider the sun beating down on them. That leads to dry-rot and lots of fine cracks in the rubber. If that gets bad enough, it can lead to a blowout. We don't see much of that because the tread wears out much sooner and the tires get replaced.
What would probably concern me more for any newer car that sits that long is the battery running down. Due to the memory circuits in the numerous computers, unless specified differently by the manufacturer, a good, fully-charged battery should be able to crank the engine well enough for starting after sitting for three weeks. Most cars can go longer than that but six to eight weeks would be pushing your luck.
Friday, October 31st, 2014 AT 11:14 PM