[Car Knowledge] How to check tire pressure and tread depth by yourself?
1️⃣ Why should I check tire pressure and tread depth regularly?
Hong Kong's weather is unpredictable, and roads are often winding and slippery (especially during heavy rain in summer). Inadequate tire pressure or shallow tread can significantly increase:
- Risk of tire blowout (either too high or too low tire pressure)
- Increased braking distance
- Chance of skidding (especially at high speeds or when crossing rip currents)
- Increased fuel consumption (when tire pressure is too low)
According to the guidelines of the Hong Kong Transport Department , the tread depth of private vehicle tires must be at least 1.6 mm . Any depth below this is illegal and you may be prosecuted at any time.
2️⃣ The Correct Way to Check Tire Pressure (Hong Kong Driver Version)
(1) Prepare tools
- Tire pressure gauge (available at garages, hardware stores, or online; digital models are more accurate)
- Air pump (available at most gas stations for free or for a fee)
- Owner's manual (check the manufacturer's recommended tire pressure)
(2) Check tire pressure
- Open the owner's manual or look at the sticker on the inside of the driver's door frame → It will list the recommended tire pressure for the front and rear wheels (usually expressed in psi or kPa).
- The common tire pressure for private cars in Hong Kong is 28 to 36 psi , and it will be higher for SUVs.
(3) Inspection steps
- Cold tire check → It is best to check before driving, because the tire pressure will be higher due to the increase in heat after driving.
- Open the tire valve cap
- Use tire pressure measurement : press the fat head against the air nozzle, and a value will be displayed (digitally or with a pointer).
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Compare recommended tire pressures :
- If too low → Go to a gas station or use a home air pump to refill.
- If it is too high → Use the air nozzle to add a little air (be careful not to add too much).
- Check all four tires (including the spare! A deflated spare tire will prevent immediate replacement in the event of a blowout).
- Close the air valve cover to prevent dust from entering.
💡Editor ’s Tip (applicable to Hong Kong) :
- In hot summer + high-speed driving: reduce the float difference by 1-2 psi compared to the original factory recommendation to avoid excessive air pressure.
- Long distance trips to the Northwest/Inland China: Adjust the tire pressure to the upper limit recommended according to the load capacity to reduce deformation under load.
- Rainy season (June-October): Too high tire pressure will reduce the grip area, too low will cause hydroplaning, so it should be just right.
3️⃣ How to check tire tread depth
(1) Legal requirements
- Hong Kong law: The tread depth of any motor vehicle tyre must be at least 1.6 mm .
- Measuring location: within the central two-thirds of the main tread groove, any point must reach the statutory depth.
(2) Inspection tools
- Tread Depth Gauge
- Or a one-cent coin (HKD$1).
(3) Coin inspection method
- Insert a HK$1 bill upright into the tire tread groove.
- If you see the entire "香港" character or too much of the lion's head exposed → it means the tread is too shallow, perhaps less than 2 mm, and you need to change the tire.
(4) Observe wear indicator (TWI)
- There are small raised strips in the tire grooves called Tread Wear Indicators .
- When the tread is worn down to the same level as the ribs, approximately 1.6 mm is left and the tread must be replaced.
💡Editor ’s Tip :
- Road surfaces in Hong Kong's urban areas do not wear out very quickly, but on mountain roads (such as Tai Mo Shan and Clear Water Bay), braking and downhill driving are common, so the tread will wear out faster.
- During the rainy season, it is recommended to keep the tread depth above 3 mm to avoid hydroplaning.
- It is recommended to check the tire tread every 6 months or every 8,000 kilometers .
4️⃣ Recommended inspection frequency (for use in Hong Kong)
| Usage | Tire pressure check | Tire tread inspection |
|---|---|---|
| General urban transportation | Once a month | Once every six months |
| Long distance/high speed common | Every two weeks | Every 3-4 months |
| Rainy season/summer | Once a month (more frequently during heavy loads) | Every 3-4 months |
5️⃣ Editor’s final warm summary
The tire is the only part that comes into direct contact with the road. Incorrect tire pressure or insufficient tread is like running in wet sneakers – one slip and you're in trouble.
Hong Kong's roads are slippery and winding, and the traffic is busy. Regular inspections are not only for your own safety, but also for the protection of passengers and other road users.
A little time checking can save a lot of trouble and money.
