Under-inflated tyres can affect safety, handling, efficiency, and tyre longevity in several ways. Here’s what happens and why it matters.
Key effects on safety and handling
- Poor braking performance and longer stopping distances: lower tyre pressure reduces the contact patch efficiency and can increase rolling resistance, making it harder to stop quickly in emergencies. This is especially evident on wet or slippery surfaces.
- Reduced steering response and cornering stability: under-inflated tyres deform more as they roll, which can dull steering input and make handling feel vague or uncertain, particularly during cornering.
- Higher risk of tyre blowouts: the extra flexing of sidewalls generates more heat, increasing the likelihood of a sudden tyre failure, especially on long drives or loaded vehicles.
Impact on wear and durability
- Uneven or accelerated tyre wear: the tyre may wear more on the edges or shoulders due to uneven load distribution and increased sidewall flex, which shortens tyre life and can leave you with less grip in critical zones.
- Increased heat buildup: continued driving with low pressure causes the tyre to overheat, further accelerating wear and raising the risk of internal structural damage.
Efficiency and cost implications
- Lower fuel efficiency: higher rolling resistance from under-inflation means the engine has to work harder, reducing miles per gallon. This can noticeably raise running costs over time.
- Higher total cost of ownership: more frequent tyre replacement due to uneven wear, plus potential fuel costs, and possible safety-related expenses.
Additional considerations
- Safety systems rely on accurate tyre data: ABS, ESC, and other traction-control systems depend on correct tyre characteristics; under-inflation can compromise the performance of these systems.
- Load and speed considerations: the safe loading capacity and heat tolerance of a tyre are influenced by pressure; driving with under-inflated tyres while carrying heavy loads or at higher speeds increases risk.
Practical guidance
- Check pressures when tyres are cold (before driving or after being parked overnight) and set to the vehicle manufacturer's recommended tyre pressure, not the maximum printed on the sidewall. Recheck when tyres are hot or after a long drive, as readings can be misleading.
- Inspect tread depth and look for uneven wear patterns; address any significant wear or bulges promptly.
- If you notice handling changes, vibration, or pulling to one side, stop safely and inspect tyres and wheel pressures.
Direct takeaway: driving with under-inflated tyres can reduce braking effectiveness, impair steering feel, increase the chance of a blowout, wear tyres unevenly, and lower fuel economy. Maintaining proper inflation improves safety, handling, tyre life, and efficiency.
