Understanding Flat Spots
When a vehicle sits stationary for an extended period, the weight of the vehicle compresses the small section of each tire that's in contact with the ground. Over time, the rubber in that contact patch conforms to the flat shape of the surface rather than maintaining its natural curve. The result is a flat spot — a section of the tire that's literally been flattened. When you drive on a flat-spotted tire, you feel a rhythmic thudding or vibration, especially at lower speeds.
Temporary vs. Permanent Flat Spotting
Not all flat spots are created equal. **Temporary flat spots** develop after a vehicle sits overnight or for a few days, especially in cold weather. The rubber stiffens and holds the flat shape but returns to normal after 15 to 30 minutes of driving as the tire warms up and flexes back into its round profile. This is completely normal and happens to every vehicle.
**Permanent flat spots** develop when a vehicle sits for weeks or months. The rubber undergoes a structural change — the internal cords and belts deform along with the rubber, and the tire can never fully regain its round shape. The vibration and noise persist no matter how long you drive.
Temperature and Duration
Cold weather accelerates flat spotting because rubber becomes less flexible at lower temperatures and holds deformations more readily. A car parked in a cold garage for two weeks is more likely to develop noticeable flat spots than one sitting in a warm climate for the same duration. Performance tires with stiffer compounds are also more susceptible than touring tires with softer, more flexible rubber.
Who Is Most at Risk
Flat spotting most commonly affects seasonal vehicles, classic cars, RVs, trailers, and any vehicle that goes through extended storage periods. Snowbird retirees who leave a car parked for several months while they travel are prime candidates. Vehicles in long-term airport parking can develop flat spots as well. Even a car left at a dealership lot for months before being sold can arrive with flat-spotted tires.
Prevention Strategies
The best prevention is to drive the vehicle periodically — at least once every two weeks for a minimum of 15 to 20 minutes at highway speeds. If that's not possible, inflate the tires to the maximum sidewall pressure (not the door placard pressure) during storage. The extra pressure reduces the depth of the contact patch and the severity of any flat spotting. Use jack stands to lift the vehicle off its tires entirely during long-term storage — this is the only guaranteed prevention method.
What to Do About Flat-Spotted Tires
If you return to a vehicle that's been sitting and feel a vibration, drive it gently for 30 to 45 minutes before making any decisions. Many flat spots work themselves out with heat and flexing. If the vibration persists after an hour of driving, the flat spots are likely permanent. At that point, the tires should be replaced for both comfort and safety. Permanently flat-spotted tires cannot be balanced properly and may develop additional structural issues. Browse Ship.Tires for replacement options that fit your vehicle and driving style.