How do Tyres Lose Pressure?
Due to the permeability process, the tyres lose a little air every day, making the pressure loss greater during the summer months. But you should also bear in mind that hard knocks can also cause the tyre pressure to drop.
Therefore, it is very important that we check the pressure periodically to ensure that our tyres are at the right level and that driving is safe. Also, the problem might come from the inflation valve because the wheel might not be well positioned in the rim and there might be cuts.
The risk of deflation can happen because of normal reasons like:
Osmosis
The compounds from which car tyres are made have minimal porosity, allowing air to pass through. In general, it takes about a year for a tyre to lose the minimum safety pressure, but if our vehicle has been exposed to extreme temperatures and suddenly the situation changes, the porosity may increase and lose more air than usual.
The average amount of pressure lost each month is 1 to 3 PSI and 6 months without checking tyres can result in the loss of between 6 and 18 PSI.
Temperature change
Higher and lower temperatures cause loss in tyre pressure, especially with lower temperatures.
- When the temperature drops by 5°, the tyres lose 2% in pressure.
- When there is a rise of 5° in temperature, the tyres get 2% more inflated.
Bumps while driving
We are often unaware that when we drive too hard over speed bumps or mount a curb, the tyre pressure suddenly increases, resulting in a loss of air in any of the tyre's elements. Therefore, if we want our tyres to last longer, it is important to avoid this type of incident.
Valve defects
If the valve is not in good condition, it will not do its job properly and will let all the air out of the tyre in just a few minutes. In general, it is not usually completely broken, but it presents some small imperfections in the central part of the mechanism and that makes it not close properly, causing the air to escape.
Nails
A car can continue driving for miles and miles with a nail embedded in the rubber of the tyres. When this happens, the loss of pressure does not occur all at once, so we do not notice it until it is already badly deflated. The point is that it is not the safest to drive with a nail in the tyre. For this reason, at the slightest loss of air that we notice, it is advisable to carry out an inspection of the tread to check that the cause is not related to a nail.
Punctures or cuts of the tyre
In the unexpected events of a cut in the tyre, depending on how much the tyre is impacted, it is highly recommended to get it immediately repaired. It can happen because of bad road conditions, sharp foreign objects like stone or glass sticking to the rubber. In most cases the objects are small and hard to avoid once close to it but they usually don’t always cut the rubber. A very strong and sharp object could create a puncture or a cut.
If you are unsure why your tyres are losing pressure it is best to consult with a tyre professional before it is too late and the tyres become unsafe to drive with.
The Tyre Pressure Monitoring System includes a valve and a sensor. They are not the same. There are two types of TPMS: direct and indirect. The indirect TPMS is using data from the vehicle's anti-lock braking system (ABS).
The Direct TPMS is a warning system that alerts a vehicle operator of an unsafe change in air pressure in the tyres. Readings are provided by pressure sensor transmitters mounted inside each tyre and sent to a central computer (ECU) for display on the dashboard. A warning indicator light on the instrument panel and an audible warning notify the driver if a 25% pressure drop occurs. If the car is equipped with the four-tyre TPMS display, they can even see the readings for each tyre. This is not the case for the indirect TPMS display.