Short and simple, it is the amount of air, measured in pounds per square inch (PSI) that fills a vehicle’s tires. The right amount of pressure in car tires is important for safety. Tires are a key safety factor in all vehicles, second in importance only to car’s brakes.
Correct tire pressure manages stability, braking and the capacity to take corners safely – all critical aspects of driving safety. On top of this, correct air pressure affects comfort while driving, the lifespan of the tire, as well as fuel economy.
When the pressure is too high, less surface area on the tire touches the ground and the car may bounce on the road. This impacts traction and the ability to stop quickly. All that bouncing also makes the ride more uncomfortable.
On the other side of the spectrum, when tire pressure is too low, more of the tire’s surface area touches the ground than necessary. This generates friction and can cause tire to wear much earlier than normal. They may also overheat.
The worst case scenario with over and under-inflated tires is tread separation. That is when the tire tread separates from the tire’s casing or body. Though this is most common with large cargo trucks, it can happen with standard vehicles as well and often leads to accidents.
Filling vehicle’s tires to the recommended pressure and checking them monthly is important. The recommended pressure is set by the car’s manufacturer and takes into consideration safety, comfort, and wear and tear on the tires.
“Experts agree that keeping the correct air pressure in your tires is as important as giving your engine a tune-up. In fact, the economic benefits may be even greater. With the right amount of air pressure, your tires wear longer, save fuel, enhance handling, and prevent accidents.” – Discount Tire
Find and seek
Finding the recommended pressure for your vehicle can feel like a game of hide and seek. When looking to check and fill their tires, most people locate the number listed on the sidewall of their vehicle’s tire quite quickly. However, that figure is the maximum PSI, not the recommended inflation amount.
The maximum PSI is the very maximum amount of air a car’s tire can hold. That is not necessarily what is best for your car’s tires, or your car.
Car manufacturers establish the recommended PSI for vehicle’s tires. The recommended inflation amount is determined by the load the vehicle is meant to carry and the tire size.
Unfortunately, no international organization oversees the standardization of vehicle tires. With no mandated or regulatory requirements in this area, it has fallen on the shoulders of the world’s largest tire organizations to set standards voluntarily. All vehicle and tire manufacturers use these numbers. The recommended tire inflation pressure for most vehicles is 32 psi to 35 psi when cold, which means the car hasn’t been driven in a few hours.
Filling your tires
When filling your tires, remember that the recommended PSI for your vehicle is very likely lower than the maximum pressure listed on your tire. The owner’s manual of your car is the best place to look for the recommended PSI for your car’s tires. If it isn’t in the owner’s manual, check for the tire placard in the glove compartment door, inside of the gas door, or on the inside of the driver’s door.