At our service centers and retail locations, one of the most frequent questions we get from customers revolves around proper tyre inflation. While everyone understands the importance of keeping tyres at the recommended pressure, one query stands out:

"My car (or motorcycle) has been sitting in the garage for a while, and the tyres seem to have lost air, even though there's no sign of a puncture or damage. What's going on?”

This is a valid concern, and often a cause of jump scare as you find all your tyres looking a bit deflated. Also, it’s frustrating to find your tyres deflated when you haven't even been driving. This leads us to the question: can your vehicle's tyres actually lose air without a puncture?

The quick and easy answer to the problem is yes indeed, tyres can lose air without a puncture. Let's look into the reasons behind this seemingly mysterious phenomenon.

6 Reasons why tyres lose air over time

The phenomenon of tyres losing air over time isn't a new concept. We've all likely experienced it with bicycle tyres, which frustratingly seem to deflate even when left untouched in the garage. The same principles apply to car and motorcycle tyres, although the process is significantly slower.

This slower deflation is due to the construction of these tyres, using higher-density rubber and advanced materials designed to retain air much better than their bicycle counterparts. The robust construction of these tyres often leads to the false assumption that car and motorcycle tyres are impervious to air loss on their own, but the reality is that they, too, are susceptible to gradual deflation over time, just at a less noticeable pace.

Here are the reasons why all pneumatic tyres lose air over time.

1. Permeation:

Tyre rubber is slightly porous. Air molecules can slowly seep through the rubber over time, even if there are no visible holes. This is a natural process and happens to all tyres, but it's more noticeable in older tyres or those exposed to extreme temperatures.

2. Valve Stem Issues:

Either the valve core (the small pin inside the valve stem) can become loose or corroded, allowing air to escape slowly. Or, the valve stem itself can crack or deteriorate due to age, exposure to the elements, or accidental damage. This can create a slow leak.

Sometimes, the valve stem might not be properly sealed to the wheel rim, allowing air to leak out from the base. Finally, while not a primary cause, a missing or loose valve cap can allow dirt and debris to enter the valve stem, potentially leading to leaks over time.

3. Bead Leaks:

The bead is the edge of the tyre that seals against the wheel rim. Corrosion, damage, or improper installation can create a gap between the bead and the rim, leading to air leakage. This is often more noticeable in older wheels or tubeless tyres that have been mounted and dismounted multiple times.

4. Wheel Issues:

Rust, cracks, or bends in the wheel rim can compromise the seal between the tyre and the wheel, causing leaks. A bent wheel can also prevent a proper seal between a tubeless tyre and the rim, leading to gradual escape of air.

5. Temperature and Altitude:

Air pressure in tyres decreases in colder temperatures and increases in warmer temperatures. Significant temperature swings can cause a noticeable drop in tyre pressure, even without a leak. For every 10°F drop in temperature, tyres can lose about 1 PSI.

Similar to temperature, changes in altitude can also affect tyre pressure. Higher altitudes have lower air pressure, so tyres can lose pressure as you go up in elevation.

6. Slow Leaks from Previous Repairs:

Sometimes, a previous puncture repair may develop a slow leak over time, even if it seemed to be initially successful. That’s why professional installation from authorized tyre shops is always recommended by Apollo Tyres.

Now that you know the reasons, how to check if your car or motorcycle tyres have been losing air due to issues other than permeation?

How to check for tyre pressure leaks?

While punctures and natural permeation are common culprits for tyre pressure loss, if you notice your tyres deflating more rapidly than expected, there could be other underlying issues. It's important to identify and address these leaks promptly to ensure safe driving and optimal tyre performance. Here's how you can check and monitor your tyres for leaks:

• Soapy Water Test: Mix soapy water and apply it to the valve stem, bead area, and any other potential leak points. Bubbles will form if there's a leak.

• Tyre Pressure Monitoring System (TPMS): Modern cars often have TPMS, which will alert you to a drop in tyre pressure. However, it might not detect very slow leaks immediately.

• Regular Pressure Checks: Manually check your tyre pressure regularly (at least once a month) with a reliable tyre gauge. This will help you identify any pressure loss early on.

• Professional Inspection: If you suspect a leak but can't find it yourself, take your vehicle to a tyre shop or mechanic for a professional inspection.

Concluding thoughts: Replace old tyres

Finally, if you're running on very old tyres, it's important to consider replacing them even if they haven't reached the tread wear limit. As tyres age, the rubber compounds degrade, making them more prone to leaks, sidewall cracking, and ultimately, the risk of sudden failure. On the other hand, if you have a relatively new set of tyres experiencing persistent pressure loss, it's wise to check for any applicable warranty coverage. Your tyre manufacturer may offer a replacement or repair policy for defects or premature issues.

At Apollo Tyres, we stand behind the quality of our products and offer a 2-year unconditional warranty on most of our car and motorcycle tyre models, providing you with peace of mind and assurance on the road. Investing in new tyres or utilizing warranty coverage when needed are crucial steps in ensuring your safety and the longevity of your vehicle's performance.

We hope you found this blog insightful, for more such information continue following the Apollo Tyres blog.