- Proper tire pressure improves safety, performance, and tire longevity.
- Check pressure on cold tires using the door placard recommendations, not maximum.
- Underinflated or overinflated tires wear unevenly and reduce efficiency.
- Temperature changes affect pressure; check when tires are cold for accuracy.
Tire pressure is one of the most important factors influencing safety, performance, and the longevity of your car. If you have ever had a flat tire, you may have noticed that a wheel isn’t completely airless. What happened is that so much air escaped from inside the tire that the car’s weight was no longer properly supported.
Tire pressure is the pressure inside the tires, usually measured in kg/m², psi (pounds per square inch) or kilopascals (kPa). This pressure is not just a technical value — it directly determines how the car behaves on the road, fuel consumption, and rolling safety.
Role and importance of tire pressure
Essential roles of air inside tires
The air inside the tire serves several fundamental purposes for correct vehicle operation:
Damping shocks from the road surface - A correctly inflated tire ensures uniform weight distribution and efficiently absorbs road irregularities. An overinflated tire provides a much stiffer handling than an underinflated one, transmitting all vibrations directly to the body.
Optimizing ground contact - An underinflated tire can give a feeling of float, as it has a contact surface with the ground that is differently shaped. This uneven deformation dramatically reduces vehicle performance, affecting braking, acceleration, and cornering stability.
Energy efficiency - Correct pressure ensures the most efficient rotation of the wheel assembly, reduces the tire–ground friction coefficient, and minimizes heat generation as the wheel moves. This efficiency directly translates into lower fuel consumption.
Preventing premature wear
Incorrect pressure prevents tire deformation and causes uneven wear. The excessive friction that occurs with underinflated tires creates heat and wears the tread more toward the outer edge. On the other hand, overinflated tires wear the central part, dramatically reducing tire life.
How to determine the optimal tire pressure for your car
Locating pressure information
The optimal tire pressure is specified on a plate located on the driver’s door frame in most cases. Sometimes the placard is in the glovebox or at the end of the door. The pressure written there should always be observed.
Difference between the recommended pressure and the maximum
Important note: There is a maximum pressure listed on the tire, but you should never reach it. This value represents the maximum pressure the tire can support without damage, not the optimal operating pressure.
The pressure recommended by the vehicle manufacturer takes into account:
- The vehicle’s weight
- Load distribution
- Suspension characteristics
- Desired performance (comfort vs. sportiness)
Factors affecting tire pressure
Temperature – Tire pressure varies by about 1-2 psi for every 10°C temperature change. Therefore, pressure checks should be performed when the tires are cold, before starting the journey.
Load – For trips with heavy luggage or extra passengers, many cars have different pressure specifications for the front and rear axles.
Road type – For highway driving, some manufacturers recommend slightly higher pressure to optimize fuel economy and high-speed stability.
Consequences of incorrect pressure
Underinflation
- Increased fuel consumption
- Accelerated tire wear
- Instability in corners
- Higher risk of blowouts at high speeds
- Longer braking distance
Overinflation
- Reduced ride comfort
- Central tire wear
- Reduced grip on wet surfaces
- Risk of damage from hitting potholes
Regular tire pressure checks, at least once a month, are an essential practice for safety and operating economy of any vehicle.
Photo credits: boardwalkacura.com, shutterstock.com, consumerreports.org
