How does tire pressure affect road safety?

1 Tire and road interaction

Tires are designed to provide a contact patch between your vehicle and the road surface, which enables you to accelerate, steer, and brake. The shape, size, and distribution of the contact patch depend on the tire pressure, load, speed, and road condition. Ideally, you want a contact patch that maximizes the friction force between the tire and the road, which depends on the coefficient of friction. The coefficient of friction is a measure of how much the tire and the road resist sliding against each other, and it varies according to the type, texture, temperature, and wetness of the road.

2 Effects of tire pressure on traction

Traction is the ability of your tires to grip the road and transmit the driving force from the engine to the wheels. Tire pressure affects traction by changing the shape and size of the contact patch. If the tire pressure is too high, the contact patch becomes smaller and more rounded, which reduces the friction force and increases the chances of slipping or skidding. If the tire pressure is too low, the contact patch becomes larger and flatter, which increases the friction force but also causes more heat buildup and deformation of the tire, which can lead to blowouts or tire failure.

4 Effects of tire pressure on braking

Braking is the ability of your vehicle to stop or slow down safely and effectively. Tire pressure affects braking by changing the amount and distribution of the contact patch. If the tire pressure is too high, the contact patch becomes smaller and more concentrated in the center of the tire, which reduces the braking force and increases the stopping distance. If the tire pressure is too low, the contact patch becomes larger and more spread out over the edges of the tire, which increases the braking force but also causes more wear and tear on the tire and the brake system.

5 Effects of tire pressure on wear

Wear is the gradual deterioration of your tires due to friction, heat, and stress. Tire pressure affects wear by changing the amount and distribution of the contact patch. If the tire pressure is too high, the contact patch becomes smaller and more concentrated in the center of the tire, which causes more wear and tear on the tread and the sidewall, and reduces the tire life. If the tire pressure is too low, the contact patch becomes larger and more spread out over the edges of the tire, which causes more wear and tear on the shoulder and the sidewall, and reduces the tire life.

6 How to check and maintain tire pressure

To ensure optimal tire pressure, you should check your tires regularly, preferably once a month or before a long trip. You can use a tire pressure gauge to measure the air pressure in your tires, and compare it with the recommended pressure for your vehicle, which is usually found on a sticker inside the driver's door, the glove box, or the owner's manual. You should check the tire pressure when the tires are cold, meaning they have not been driven for at least three hours or more than a mile. You should also inspect your tires for any signs of damage, such as cuts, cracks, bulges, or punctures, and replace them if necessary. You should also rotate your tires every 6,000 to 8,000 miles to ensure even wear and extend their life span.

7 Here’s what else to consider

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