Flat-Spotting: Why Tyres Develop Flat Spots During Storage

When cars sit unused for days, weeks, or even months, it’s common to notice a slight vibration or thumping sound when you first drive away. Don’t panic — this is most likely flat-spotting, a temporary deformation of the tyre caused by the vehicle’s weight pressing on one spot for an extended period.

Let’s explore what causes flat-spotting, the difference between temporary and semi-permanent flat spots, and how to prevent them.

What Is Flat-Spotting?

Flat-spotting occurs when a tyre remains stationary under the vehicle’s load for a prolonged time. The section of the tyre that touches the ground becomes slightly flattened due to pressure and temperature changes.

How It Happens

While driving, tyres constantly flex between a loaded and relaxed state — hundreds of times per mile — generating heat that keeps the rubber supple.
When the vehicle stops, the tyres cool down, and the rubber stiffens. If the car stays parked too long, the area in contact with the ground may flatten slightly.

This effect is more noticeable when:

• The car is parked in cold temperatures

• Tyre pressure is low

• The vehicle carries heavy loads

• The tyres remain stationary for long periods

Two Types of Flat-Spotting

1. Temporary Flat-Spotting

• Common after parking for a few days or weeks

• Causes a mild vibration or thumping noise when first driving

• Disappears after several miles as the tyres warm up and regain shape

Example: Leaving your car parked at the airport for a week may cause slight vibration that fades once you’ve driven a few kilometres.

2. Semi-Permanent Flat-Spotting

• Occurs when a vehicle remains parked for a month or more

• Typical during long-term storage (e.g., winter hibernation or shipping)

• Worsened by underinflation, high temperatures, or heavy loads

• The tyre may not return to its original shape through normal driving

If you suspect semi-permanent flat-spotting, contact a tyre specialist or garage. They can assess whether the tyre can recover or if replacement is required.

How to Prevent Flat-Spotting

Flat-spotting is easy to prevent with a few simple precautions, especially before parking your car for an extended time.

1. Maintain Correct Tyre Pressure

• Ensure tyres are inflated to the manufacturer’s recommended levels.

• Underinflated tyres are more prone to deformation.

• Before long-term parking, consider increasing tyre pressure by 3 PSI to reduce the risk — but never exceed the maximum cold inflation pressure.

2. Avoid Overloading the Vehicle

• Excess weight puts additional pressure on the tyre contact patch, accelerating flat-spot formation.

3. Move the Vehicle Periodically

• If possible, roll the car a short distance every few weeks to change the contact point on the tyre.

4. Use Tyre Cradles or Parking Mats

• Specially designed tyre saver ramps or storage mats help distribute weight evenly and reduce pressure on a single area.

5. Adjust Pressure for Long-Term Storage

• When storing a vehicle for several months, slightly increasing tyre pressure by about 3 PSI helps maintain shape.

• This also reduces heat buildup when you resume driving.

Pro Tip: A 3 PSI increase in tyre pressure lowers tyre operating temperatures, reducing the likelihood of flat-spotting after long-term storage.

Summary

Key Takeaways

✅ Maintain correct or slightly increased tyre pressure before long storage
✅ Avoid overloading and move the car occasionally
✅ Use parking mats for extra protection
✅ Never exceed the tyre’s maximum pressure rating
✅ Seek expert help if vibrations persist after several miles of driving