Tyre pressure is often underestimated because the tyres may still look fine to the eye. In reality, even a small deviation can affect how the car behaves on the road and how quickly the tyres wear.
Pressure that is too low increases rolling resistance, raises fuel consumption and causes faster shoulder wear. Pressure that is too high can reduce grip and make the ride harsher, especially on poor road surfaces.
The smartest approach is to measure pressure with cold tyres and follow the vehicle manufacturer's recommendation, not a random number from the tyre sidewall. Front and rear pressures may differ, and the recommendation may change with a full load.
Regular pressure checks also help you spot issues earlier. A slow pressure loss can point to a screw, a leaking valve or a wheel sealing problem before it turns into a roadside headache.