If you run separate winter and summer tire sets, you'll have one set in storage for six months at a time. Stored poorly, even a brand-new tire can develop dry rot or deform in months. Stored properly, the same tire keeps every bit of its performance for years.
Five rules for storage
1. Cool
Below 80°F if possible. Heat accelerates the chemical breakdown of rubber. An attic, an uninsulated shed in summer, or anywhere near a furnace, water heater, or dryer vent is bad news.
2. Dry
Humidity by itself doesn't damage tires, but it does encourage mold and mildew on the rubber and steel cord rust over years. A garage corner is fine. A damp basement isn't ideal.
3. Dark
UV light is the single fastest accelerator of tire aging. Don't store tires anywhere they get direct sunlight, even through a window. If they must be in a lit space, use tire bags or covers.
4. Away from ozone
Ozone — produced by electric motors, fluorescent lights, and welding equipment — eats rubber. Don't store tires near the furnace, near a sump pump, or in the same room as a workbench with grinder/welder use.
5. Off chemicals
Don't stack tires on top of oils, gasoline, or solvents. Petroleum products soften rubber. A clean concrete floor is fine — but a corner where oil leaks pool is not.
How to position them
- Mounted on wheels: stack flat OR hang from a rack. Don't store mounted tires on their sides on the floor — pressure deforms the bead seat over months.
- Dismounted (loose tires): store upright on the tread, in a row, rotating each tire 90° once a month to prevent flat spots.
Pressure during storage
Mounted tires holding pressure during storage will leak down naturally — that's fine. When you remount them on the car, just fill to the door-jamb spec. Don't over-pressure for storage; it does nothing helpful and may stress the bead seat.
Tire bags — worth it?
Yes, especially for indoor storage. They block UV, contain ozone exposure from outside, and keep dust off. The cheap plastic bags from a tire shop work fine — a $20 set lasts years.
A tire that comes out of storage in the same shape it went in is one less thing to think about in spring.