Tires: Storing Cars, cold temperatures, high temperatures

Question
I have heard that it is bad for the tires if a car is left in one spot for a long time.  How long is long?  How often and how far should a car be driven to keep life in the tires if it goes long periods without use?

Answer
Sara,

This is a complex issue with many facets.

First, any time a vehicle sits, it is starting to get a flat spot.  It is very temperature related.  Clearly a week of sitting shouldn't cause an issue, but a month in high temperatures is enough to get a detectable flat spot.  2 months in even cold temperatures would have pretty much the same effect.

It would take about 30 minutes of sustained driving to heat the tire enough to remove most traces of a flat spot - followed by a cool down before it sits for an extended period.

Even moving the car forward a foot is also acceptable - but only a foot, not 2 feet!