Do you ever feel a ride disturbance or shimmy during the first few miles of driving after your vehicle has been parked for a few days, weeks or months? Then, after you drive a couple of miles, the ride smoothes out and feels Ok. This condition is often called flatspotting because it is used to describe the temporary tire flat-spotting that can occur when a vehicle is parked.

Many heavy-duty, high-performance, high-speed-rated and racing tires have memory. They continue to remember the position in which they were last parked after they are driven on again. Unfortunately their memory can become a problem when the tires experience big swings in ambient temperature, have been parked overnight in cold temperatures or parked on a rough surface, or are parked for an extended period of time, because lack of use is what can cause tires to flat-spot.

As they roll, tires go from a relaxed state to a loaded state about 800 times every mile. This constant deflection generates heat that makes the tires more flexible. However, once they are parked, the spot in contact with the ground (the tire's footprint) flattens, as it is pressed against the road's flat surface as the tires cool. This is what generates flat spots. Until the tires warm up again, the flat spot on each tire can cause a ride disturbance that will be felt for the first few miles the next time the vehicle is driven.

Flat spotting can be temporary (the tire will round out as driving warms it up) or in the most severe cases, permanent (in which the tire's ride quality is effectively destroyed). A flat-spot's severity is often a function of the tire size, internal structure, load, ambient temperature, roughness of the ground and time spent stationary.

Low aspect ratio tires have less sidewall flex due to their short sidewalls and much of their load carrying capacity is absorbed by the deflection of their wide footprints.

The tread compounds and firm, nylon reinforced internal constructions used on high performance and high speed-rated tires are more susceptible to flat spotting.

Heavy loads and too little air pressure in the tires (under inflation) will allow them to deflect more where they come into contact with the ground. This allows even more deflection, increasing the severity of the flat spotting.

Cold ambient temperatures make rubber compounds stiffer, increasing their tendency to flat spot.

Rough surfaces make a print on tires even if the car was parked for short periods.

The longer tires remain stationary, the better they remember the position in which they were last parked. Tires on vehicles stored on the ground for many months can be permanently flat-spotted.

Minimizing Flat-Spotting

While there is no way to completely avoid tire flat-spotting, except using a very well researched and proven material like the ones used by ALTairEGO.


ALTairEGO have a wide range of specialty products designed to suit your car, from classic, sports, supercar, truck to heavy weight.